Building new system starting with power amp. What would you choose ?


This is not how it usually happens, but what if you simply must have a particular amp and then move with upgrades in both directions? Let's assume that the only source will be RTR deck, so no preamp will be needed.
The price range..how about $15k new or used ?
This is a hypothetical exercise, I am personally not prepared for that yet. However, it would be, theoretically, perfect minimalist audiophile set-up. 
I myself would probably choose either Lamm monoblocks or Gryphon stereo power amp, both used of course.
inna
I have Pass xa30.8 Wilson Sabrina and a Nagra 300i with some B&w both really nice

What is also really nice is the Devialet amps a mix between A and D class
Pass Labs INT250.  It is integrated at 250 W/channel RMS and nothing else will come close.
"Within that budget, I would be looking at a pair of Coincident 211PP Dragon MK II monoblocks"

I would do what @nordicnorm says.  In fact, I did.

Andrew
Depends on the speakers. I could suggest if I knew which speakers  you are using