SS 80 to 125 wpc -- NAD, Adcom, B&K, AVA, McC ?

I'm thinking about upgrading from the NAD C340 50 wpc integrated currently driving Vandy 1b's in my downstairs system. (My long-time favorite Dyna A-25's are going to the upstairs system.) I like the C340 and it drives the 1b's OK, but I'd like more depth in the bass, and a sound which remains at least on a par with the C340 in terms of clarity and detail. System, mostly played at moderate volumes in a medium-size living room, is used to listen to small-group jazz (lots of Jim Hall), with some rock, folk and classical. Main source is Cambridge Audio D500 CD player; MAS Gray IC's and Cardas Twinlink on the CDP; Signal Cable speaker cables. The general idea is to run the signal out from the C340's preamp section to a more powerful power amp in the 80 to 125 wpc range, and perhaps upgrade the CDP and preamp later on. Candidates: NAD C352 or C370 integrated, or NAD 214, C270, or C272 power amp; Adcom GFA-545II, GFA-5300, GFA-5400; B&K ST-140, ST-1400 II, or ST 125.2; AVA (Audio by Van Alstine) OmegaStar 240EX; or McCormack DNA-0.5, DNA-1, DNA-125. There seem to be many testimonials to how well McCormack amplification goes with Vandersteen speakers, particularly with Audible Illusion or other tube preamps, but McCormack amps don't come up for sale all that often, their price is toward the high end of what I was thinking about spending, and a good tube preamp would increase the cost of the amp upgrade substantially. Your suggestions?