Dazed and Confused - Upgrading System But Too Many Options!

gdnrbob,
Thanks for the input.  I have bought from Agon before and will certainly again.  I guess part of me feels like if I go to these dealers and pick their brains and listen to their equipment and spend their time that I don't want to turn around and buy used from Agon.  But I haven't done much of that yet.  Only one visit and a slew of emails with another.  

I enjoy THIS quest because I'm going to get some shiny new toys and there will most likely be bourbon involved.  I don't want to do it all the time because, for one, I can't afford to constantly be buying and selling, and two, I don't get tons of listening time.  But when I do, I want to thoroughly enjoy it.

If I had to say what is missing it would be the soundstage and separation.  The B&K is a great amp with plenty of power (140w) and it's very warm.  It was far from an entry level amp when I bought it.  The Rotel pre is very entry level and is easily the weak link.  I could probably upgrade some interconnects too.  I definitely want to go digital and get a music server either way. 

I agree that the Rotel pre is the weakest link in your current system( not considering speakers, not familiar with them). I once owned the B&K ST140 and thought it great. Owned it for 25 years.

That said, there are many very good integrateds on the market now. Been down the same road and understand. Only you can decide which way to go. 

I would listen to the LS-50 monitors before you decide.  I found them bright, quite bright at times.

I appreciate your loyalty to the dealers who guide you, it helps keep them in business.
I was thinking you were using reviews and online opinion to do your upgrading. 
With regard to 'soundstage and separation':
As I said before, the Preamp is probably your weakest link and will probably be the most significant (in sound) change in your system.
With regard to digital:
I built a micro PC for streaming and bought a Schiit Dac running into McCormack Pre and amp. It sounds great. In fact, I love streaming Spotify and Classics Online so much, that I hardly ever use my CD library anymore. I know there are purists who swear by vinyl, but, being of the LP generation, I can't believe how wonderful not having to get up and change a record can be. Also, I get to listen to composers that I never had the time or inclination to listen to before.

Thanks for they continuing the thread guys.  I understand the LS50s have a long break in period.  I read something like 300 hours.  The dealer is pushing a pair of demo KEF R300s hard and provided an excellent price ($1,100).  I would be able to demo the KEFs.  He also gave me great prices on all the 851 components and the LS50s.  Maybe not as cheap as used on Agon but definitely competitive.

Unfortunately there is no place around me that has the 851 series available for an audition.  A few places within a couple hundred miles carry them but they are not on the demo floor.  So I will have to go on faith of reviews and research for the CA 851s.

Right now I'm leaning on getting the 851W (200w) and 851N and keeping my speakers.  I would then have my B&K and Rotel for the basement on an old pair of Advents I built from a kit in high school.  We will be getting a new TV and component rack so it will be my second listening room (for when the fam kicks me out of the living room).

Another option is to get the 851N and KEFs and an even cheaper option is to just get the 851N and plug it into my B&K.  As you can tell, I have pretty much settled on Cambridge Audio and KEF.  It's just what will be the winning component combination.  

I can really do without the tt because my old record collection is in such bad shape.  I can still move the tt to the basement. 

The dealer is working very hard to get me the right system so I will reward him. The last thing I want is to buy used after all this and then have to take it to the dealer if/when it breaks. 

Thanks again to everyone for the help.

Ken