Wilson Sophia 2--- VTL S-150 or Ayre V1-xe?

VTL also still produces the little MB-125's. These mono's use the EL-34's , where as the ST-150 uses 6550's. The 125's may have the same power, and the Wilson may really sing w/ the EL-34. BTW, their prices are close, $5000 I believe. FWIW, the 125's also have the Triode mode like the ST-150. That said, I am not confident that either in Triode would be enough power. Perhaps it may be, but I am not sure. At the ST-150's price point, there is also some other interesting choices IMO. Maybe a C-J Premier 12, seen under 3K used, or a Quicksilver V-4.

CJ 350A would be very good. Don't expect best bass quality with any tube amp, trade off for midrange quality. Choice depends on priorities, if you want full volume and best bass go SS, if tube sound is priority then go for as powerful a one as fits budget. Large Audio Research are excellent but pricey. Big Krell probably best bass but also very high.

I have an Ayre V1xe, and am extremely pleased with it. Although solid state (without the maintenance therein) it doesn't have that solid state sound. There is one caution..the amp sounds its best used in balanced mode.

Depends on your space.

I have been running my WP7s for several years with the 100 wpc Music Reference RM200, which is a glorious combination in my relatively small room. Bass quality is exceptional, but not Krell-like. Of course, the RM200 is not your average 100 wpc tube amp.

I've heard the RM200 with Sophias and it works great as long as the room is not too large. Since the Sophias are relatively efficient a gigantic amp should not be necessary unless you intend on habitually playing them at jet plane levels in a large room.

If your happy with the highs and mids why not spend your money on a pair of subs then you'll have everything you want without the hassles of equipment buying/selling and associated loss of monies.