Amp or speaker first, upgrade

Hello audiogoners, it's the Brahman on a beer budget with an upgrade dilemma.
I currently have a Krell s300i, a pair of Definitive technology bp8080 as my system.
Now, I want to upgrade both but, one at a time and was wondering which of the two 
components should I dispense with first?
Here are the amps I've been looking to audition, Icon Audio st40 mkiiim, Luxman 505ux, McIntosh Ma5200
and Prima Luna Dialogue Premium. As you can see there is a solid state in the bunch.
As for speakers, I'm interested in the Vandersteens 3a signature, the Sonus Faber Venere S, and the 
Wharfdale Jade 7. I know this topic has been brought before so I'll welcome some new and refreshing
ideas and comments! Thanks a bunch Audiogoners!

I own the Vandy 3a sigs and enjoy them immensely. I have no experience with the Definitive speakers, so I cannot give any comment to their sound
For me, I would consider upgrading the speakers first.
If you think you will go with Vandy's, I suggest moving to the McCormack amps and preamps as they mate with Vandersteen speakers nicely. They also can be upgraded by Steve McCormack, should you want, in the future.
in your particular situation I would do the speakers first
Speakers "usually" have the most impact.
Absolutely speakers.  I have owned Def Tech speakers, and when I upgraded them to a far more sophisticated speaker (Rockport Mira Monitors) I was extremely pleased.  Overall I was not particularly happy with my def tech speakers (I had the Mythos STS Super Towers) and I kept them for only about a year and a half.

The Krell amp you have has more clout amongst integrated amps than your def techs have amongst speakers.  I'll bet that Krell will really impress you with some good speakers.  In fact, I would recommend putting all of the budget for the amp and the speakers towards the speakers, and keep the Krell for a good while longer.  Sure, you may upgrade it eventually, but in my humble opinion, you'll get more improvement in the system with an outstanding speaker than you will with a speaker and amp upgrade sharing funds.

these may or may not work for your budget or your interest, but there is a pair of Wilson Watt Puppy 7s in excellent condition on agon that have dropped in price of more than a grand over the past few months.  At 4 ohms, your Krell's 300 watts should be fine with them.  I auditioned them (not the exact pair) and was very impressed!. I wanted to buy them, but I was drawn to a different pair of Wilsons closer to home.  As I said, these may or may not be for you, but worth a look and a ponder anyway.
As someone who owned Wilson's,  I  encourage you to listen to Aerial 7Ts and Revel F208's depending on your budget.
Amp or speaker first, upgrade

I would do speakers first, as your Krell even though it’s a smaller one it still has good current, being Bi-Polar(BJT) output stage, and will drive most speakers out there and it’s not a bad amp, very good in fact. 

If you do amp first and it’s not as ballsy (current) as the Krell then it may not drive future speaker.

Cheers George

Find a pair of speakers that you can't live without. Speakers determine most of the sound of your system. Alan
Your amp can drive tough and big speakers. If you don't mind going for used, Aerial 10t stay with me for the past 16 years with not even a second thought of replacing them.

the 10T is an awesome speaker, as is the similar sounding Aerial 8 or 8b
also be aware that there were a few changes in the 10T but no model designation change. there were also two versions of the 8 before it became the 8b
Wow fellow audiogoners, I'm overwhelmed by all the responses!
This indeed is interesting and refreshing just what I hope to hear!
Yes, I'm seriously considering the Vandy 3a sigs but also looking at the Revel f208. Glad to hear most of you suggest I hang on to the Krell as I do really like this amp a lot. I'll be looking at the Aerials mentioned by an audiogoner, and the Wharfdale Jade 7?
Well since everyone is leaning on speaker upgrade then speaker upgrade it shall be. Thanks again guys, cheers and happy music listening!

enjoy the quest
You have gotten some good responses so far and I agree that the speakers will make the greatest difference in sound.  One other thing to consider:  single-driver speakers.  I have had numerous multiple driver speakers including some mentioned above, up to $42K retail.  I recently bought some single drivers and had a friend make some simple laminated mdf cabinets, total cost $1600.  I can report that I will never go back to multiple driver speakers; well, I highly doubt it anyway.  Just something to think about.

As for speakers, keep the Krell (tested at 2x190W 8ohms both channels driven and 324W into 4ohms) as I stated above, and get full range ESL’s (electrostatics) eg: ML cls/quad etc, or next best, full range ribbons eg: Maggies ect.

And add a/some S/H active sub/s from 100hz-150hz down (these are cheap. Far better than a full range single driver or multiple driver, and the ultimate in transparency and dynamics and your Krell will yawn at having to drive them.

Cheers George

Speaker first than a great amp enjoy!!

Of your selections, the Vandersteen 3A Sigs would the ones I would go with; I am a Thiel owner now but have owned Vandersteen in the past and greatly enjoyed their sound. 
IMO your speaker choices are vastly varied - Vandy 3A, SF Venere S, Wharfdale Jade7. 
The Vandy 3A is a time-coherent speaker (I'm a huge fan of time-coherent speakers & would go for such a speaker any time, any place) & so I'd recommend this speaker over any of your other choices. Time-coherent speakers render the music in such a natural fashion that it becomes very difficult to listen to any other speaker type once you've listened to a time-coherent speaker. Time-coherent speakers sound right every time with every music genre.
I note that stevecham is on the same page - switched from Vandy to Thiel which is also another time-coherent speaker (atleast those that were manuf when Jim Thiel was around & running the company).
Want to thank the audiogoners who posted comments after I responded to the previous bunch, you folks are awesome!
As for bombaywalla comment on the time-coherent design of the Vandersteen, that's a good point as I never ponder on that before I made my speaker selection good catch bombaywalla thank you!
Just thought I mention again that everyone's response was on target.
Thanks again audiogoners !
Regards, barbman

You've got waaaay too much money invested as is.  I suggest you dump both the amp and speakers and get into a Linkwitz LX521 system.  Google it.  Read about it.  Find someone in your area who has a set and go listen.  It will be the very last speaker system you'll ever want.

I will also add my vote to keep the Krell. It’s an excellent piece of equipment if you know what to expect from it. The Krell equipment use bipolar circuits (as opposed to FET based circuits). They are higher bandwidth and higher resolution circuits so make sure you have a very smooth/refined source (i.e. DAC) as the Krell can be very revealing of any flaws or digital like character coming from the DAC (there’s nothing laid back about the Krell). That being said, the Class A preamp circuits are excellent. If you want laid back, look into something like the McIntosh stuff, which is very full-bodied, but very laid back (very forgiving of a bad source). To me, the McIntosh stuff just has no excitement or life, but that’s my personal preference - as many love McIntosh.

I have never been a fan of Definitive Technology speakers. They tend to be very bright in the high frequencies and the bipolar speaker design can cause the highs to be very messy and bright/harsh. There are certainly much better speaker choices to select from.

The Aerial 10T’s are a very nice older speaker. I know somebody who has them and they are very nice with the Krell KAV-280p preamp he uses. They are looser in the high frequencies (not as controlled) and they do not have as much midrange body as something like a B&W speaker, but they are very nice. I have not heard the newer 20t that uses a ribbon tweeter.

Just want to let the audiogoners that responded to my questions, I respect every reply, suggestions, ideas and so forth. I put all these ideas in a large audio pot and see what comes out that most agree on. Well I'm gonna keep my trusty Krell amp and sell my Definitive Technology speakers and pull the trigger on a pair of Vandersteen 3a signature!
As one audiogoner suggested, I can upgrade the amp later down the road?
Hey guys remember, let's not get caught up to much in the hardware otherwise we'll never enjoy the software, the music we cherish and love!
Thanks again guys, enjoy the music!
Regards, barbman

Way to go!
I, too, have the Vandy 3a sigs. I remembered listening to the original 2's back in the early 80's, and after a 30 year hiatus, I finally got back into hifi. I have to say the Vandersteens have met and exceeded all my expectations. Enjoy. Should you need any help in setup, contact JohnnyR on Agon(Audioconnections, I believe). Mr. V will also answer your questions personally, but he can be a bit brusque.