Classe CA 200 with b&w CDM-7NT

Actually CDM 7NT sounds better than most 8... series. 805D is one of few great sounding speakers built by B&W.
CA200 is great amp way superior to Zamp. It's descent price, but if you find cheaper, why not. Classe amps are fully balanced so I'd suggest using XLR connectors if you decide to get one.

Wattage is sometime misleading. Personally, I think the class of the amplifier and its current/amperage rating matter more. I've gone through a lot of speakers(Paradigm ref100, B&W 804N, 805N, 685, 801N Paradigms) and power amps(citation 7.1, bryston 7BST, CAL MCA2500, McIntosh 501, Krell 650mcx, Wadia Powerdac 151) and believe it or not, I ended up with the Krell 650mc (650w/c) for my 801N and the wadia powerdac151 (25w/c) for my B&W685. Having said that, I think the 200w from your classe is more than enough for your 7NT. Connect them with a pair of Musicwave Super from Transparent and you'll be enjoying it for a long time. Save your money for music because at the end of the day, system is useless without music.

I think it's a good match. IMHO, if it's in excellent condition with OB&M, the price seems on the high side of fair.

I had the B&W CDM 7NT's just jumped up to the 804s's what a big improvement. With B&W speakers they do require a good class A amp. The more power you can put through them the better they will sound. I run all Krell with the FPB 400CX and I couldn't ask for a better sounding system. Krell is a good match for B&W speakers. If you really want a big improvment put a good sub with those speakers you will really be impressed.