Which Proac would sound better

consider the response 3. i think it's the best pro ac ever made.

My best bud has the Response 3 driven by top notch ARC tube gear and a topflight analogue front end. Great speaker but dated. Will probably require refoaming the woofers at this stage. A very nice speaker and a great bargain (can be gotten around 2K at this point) but if you have between 5-8K to spend the DA-1's are soooo much better. So are the D38's (but not the D25's). Why not consider the 3.8, which can be gotten around 4K and is nearly the equal of the D38 and way better than the D25? Of course, all IMHO.

Have you considered the Wilson Benesch Curves? In the 8k range...I have heard these speakers with Levinson pre/pro combination, Ayre Universal player, SME 20/2 turntable, Audio Research phono preamp. Very sweet system...and this was in an acoustically correct room about the size of yours. You will not find alot of reviews of the WB Curves...the best way to know is to demo them yourself.

In your price range, you might also want to check out a used pair of Wilson Sophia 1s or a new pair of Proac D38 (I do love the Proac sound!).

Best of luck.

Go for the D38. An absolutely wonderful speaker. They should integrate well in a room of your size.