Try your MC275 first before you spend your money.
The PASS will work fine, as will any high current SS amp, although the PASS will probably sound better than most.
Back in the day, many liked Classe' amps with B&W, maybe because quite a few American audio shops that sold B&W also sold Classe', but you can probably do better, IMO. Here are three options;
1. If you like Class A power, you can consider something from the PASS XA series or, for an option at a much lower dollars per Class A watt price, try something like the Clayton M300s I previously owned.
2. For high power at a reasonable cost, a used McCormack DNA-500 would be a bargin. In stock form, many found it to be competitive with the best of SS and used they are going for about $3.5-4K. Steve at SMc audio (the original designer of that amp) has a few upgrades that can bring that amp to an even higher level of performance.
3. I just recently auditioned the new 400 wpc, NC1200 Ncore Class D amplifiers by Acoustic Imagery, the Atsah monoblocks. I was impressed and found them to be fully satisfying and quite musical, if just a touch below the absolute performance level of the Clayton M300s, based on a direct comparison in my system. Call Michael at TweekGeek and ask if you can audition a pair in your home with your speakers. You may find that you do not need to look any further.
I hope this helps. Options are almost endless so take your time. If it were me, I would probably start with an audition of the Atsahs and then if those do not work for you, any of the other recommendations above, including the PASS, should sound good. Also, there are for sure other good amps not mentioned in this response. Good luck.