In need of some Amplifier advice. Is therereally any point in it with my current setup?

Hello. I have posted in the past, but have since learned a little bit more from reading audio forums, and doing some research and have come to somewhat of a juncture. 

I figure I could "stair step" up on my own and enjoy the ride, or, ask those who have most likely been where i am before and skip a few steps =). 

My current setup consists of a Yamaha adventage-A3070 AV receiver (150wattsx8ohms 2chd), and 2 Polk LSIM707 towers. 

I've been looking at used Classe amps here on audiogon, or possibly a new parasound Halo A21 power aplifier,  and have thought about purchasing them. 

My question is, would my Yamaha advantage 3070 even be a sufficient pre-amp? It has pre-outs for all channels, and it also has an ess sabre DAC for my digital flac files. Or would using the Yamaha as a pre completely destroy the sound of the power amplifier? Essentially wasting $1,000-$3,000. 

My other question is pretty obvious. Should I trade up, just spend the $1,000-$3,000 on better set of speakers I've been eye balling like  the EMT-LFT8s, and stick with the Yamaha receiver's power for now. 

If it were you. What would you do? 

I have listened to the Parasound Halo integrated, Peachtree nova 300 integrated, Rotel RA 1952 integrated, paired with my Polk LSIM707s. I know these aren't the greatest speakers, but, they are full range. 

As far as the integrated amps go, I like the Parasound Halo and Rotel over the Peachtree. 

The Peachtree seems more neutral and dynamically bland when compared to the Rotel and Halo. Honestly, I think my Yamaha 3070-AVR sounds better than the Peachtree and seems to almost have as much power. 

I like the punch and precise accuracy of the Rotel when listening to rock and most music made post 1990.

However, i prefer the parasound when listening to vocals like Norah Jones, solo piano, jazz, and classic rock.

The Rotel almost seems to take the classic out of...the classic. The best way I can explain it. When listening to The Who, Crosby stills and nash, and a few others everything feels forced, even when tonally adjusted, and to my ears it takes away from the classic feel and tries to bring them into the 90s. Some of this may be the polks, but I didn't have the same sense with the Parasound.

Also note that I was using Flacs and MQA files through the 3 integrated's DACs. I do not use turntables or SACD players.

Between the three I would pick the Parasound Halo hands down.  

I will be demoing some Focals, Martens, Rogue hybrid amps, and Harbeths soon. 
Nice!  I believe that the dealer in Moore that I sent you carries all of those.  In a little higher price range, the new Anthem STR integrated amp is getting nice reviews, and it also has home theater bypass, so that you can keep your Yamaha 3070 in action. 
Yeah I saw that integrated and have thought about it if I can find a place to demo it.  The Halo also has the bypass option. As does the rotel I believe.

The dealer you referred me to is whom I'm going to be demoing the speakers and rogue amps I mentioned with when we both find the time. 

Just reading and catching up on this thread.  One comment I will make is I think your choice of Yamaha 3070 is a very good one.  I think the Yamaha is the most neutral and most natural sounding receiver without pushing any particular characteristic (for example, Anthem receivers tend to over-push high frequencies like a ribbon tweeter, Marantz receivers are to warm/slow losing resolution when everything sounds like mush).  However, every single receiver will be limited on the aamplifier section.  They ALL will have very limited size power supply and all will only have 2 output transistors per channel (one transistor for positive waveform and one transistor for negative side of waveforms).

adding an external amplifier will enable you to drive the speakers much better (even on easier 8 ohm speakers).  Amps will have massive power supplies, huge transformers, large capacitance such as 50,000uf to 100,000uf (compared to something like 2 x 6800uf of a typical receiver).  They will have anywhere between 6 and 12 output transistors per channel (the Parasound A21 has 8 transistors per channel).  You will have much more clarity, attack, slam, punch.  Adding an amplifier to your Yamaha 3070 can be a great first step.  That being said, the Yamaha will have conventional op amps in a clean sounding fashion.  I would be careful of amp choice and would stay away from ultra-clean stuff like typical Class D or Bryston type amps.  Look for a warmer or “Class A” type amp.  Parasound A21 is an excellent choice.  I’m sure there are others.  I believe the Parasound uses a fully discrete jfet input stage ran in Class A mode.

If if you were interested in Class D, only 2 recommendations.  PS Audio Stellar Gain S300 with Class A input stage.  Or Nord One Up with Sparkos discrete Class A op amp input stage.

A comment on on the Parasound integrated.  It is a very nice integrated if you need all the features.  It is basically an A23 amp with a larger transformer and a P5 preamp put into a single chassis. It is very nice, but it is not an A21 amp!  The P5 preamp is okay, and is a great buy if you need all those featurs, but there definitely better choices.

i would say to start with something like a Parasound A21 with your Yamaha 3070.  You could always add a really nice preamp later and configure the system as a “hybrid HT/2-channel system”.

many have recommended to start with speakers.  Changing speakers can definitely have a significant impact on sound.  But the amplifier is also a very important piece and can really make any speaker “sing” much better.
If you really wanted an integrated, I would look at the Hegel. Like this H160:

It is pretty much the equivalent of the Parasound Integrated (but without phono preamp and sub crossover). Hegel also has limited analog inputs (1 rca, 1 XLR, 1 ht bypass). However I think the Built DAC is much better. The Parasound Integrated/P5 DAC is pretty much junk. I think it would be a better end result than the Parasound Integrated. There are more expensive integrated, of course.

The Hegel will be very nice, but personally I would rather go with A21 amp and a very nice preamp.