Bryston 4BSST, or 7BST's w/B&W M802SIII's?

I have a pair of B&W M802SIII's that I've been thru a few amps with; slowly learning that they like a lot of SS power. My latest is a C-J MF2250 (125 wpc) that is a very sweet little amp, & my best result so far with the M802's. However, the system still sounds a bit congested on orchestral or big band music played at "realistic volume levels". One amp I'm considering is a C-J MF2500. But I've always wanted to try a Bryston, & have narrowed it down to a 4BSST, or 7BST's; with the 7BST's going for a few hundred $$ more used than the 4BSST. And to be honest, I haven't really thought thru the dues or expense of the extra cables with mono-blocs, but I tend not to spend big bucks for cables anyway. And it might come down to "opportunity", as well.

My listening room right now is only 12' by 16'. Rest of my system: C-J PFR pre-amp, Cary 303-200 CDP, Fanfare tuner, Rega P25 w/Benz Glider. Thanks in advance for any advice!
On that speaker the more power the better! If you can get the 7B go for it.
I love my 7B-ST's, and have never tried them with B&W nor comparison shopped against 4BSST. But what extra cable are you talking about? One more power cord, that's it. You may even say $ by running shorter speaker cables.
The Brystons workd very well with the M B&W series. I owned the 803s that I recently sold, other amps are Krell, Pass and Sim Audio. I am not familiar witht eh newer Bryston amps but the Krell, Sim and Pass were better amps than the older Brystons.

Happy Listening
At one time I had a 4BST powering Thiel CS7s and when I upgraded to the 7BSTs the difference was amazing. The reason I upgraded initially was becuase I could easily get the clipping lights to turn on on the 4BST on some recordings that had a lot of bass content. The 7BSTs were much better able to produce the current needed for, and the detail coming from, the speakers. Focus and listening ease was much improved. Bass was faster and more extended and the highs were sweeter. Overall, I would go for the 7BSTs if your budget can swing it.
Another vote for the 7BST's.
125 watts per channel is a toy. And the 4b has balls but lacks ultimate in the room presence. Get some real power for those power hungry speakers. How about a used Classe CA-400.