200w/ch stereo amps: best 1 for under 2000 used?

Sean is right. You're gonna' need a LOT of power. Probably more than you may think.

If you're in love with your speakers and don't want to get something that's more efficient, you may also want to consider the Sunfire Signature (600 watts X 2). There is one listed here on the AudiogoN for exactly $2K. I've heard the non-Signature (300wpc) and it was outstanding. Every bit as good as the Bryston and better than the Aragon (IMHO). At more than twice the power of the Bryston, I think it might be a good solution to your dilemma.

That's a HUGE room!!

I'll say the Classe CA-200. It's smooth, like the McCormack and the BAT. Amps is what Classe does best. Give one a listen, if you can. Can be had used for about $1500 or less.

I'm plugging the local product here - but a very underrated option in your price range is the Plinius 8200P (which is the power amp part of the 8200). I have been playing with one (hey, they are only USD1,000 here you know - I am thinking of getting three of them) and now that it has burned in, it beats many of the amps that go for USD2000 second-hand. It has recently bettered a Krell KSA100S (smooth, but lacks PRAT and dynamics), a McCormack DNA-1 (just a little too crisp and grainy, but good PRAT), Muse 180 (smooth and easy, but with a soft grain and dynamically constrained), and a Aragon 4004 MkII (not in the same league of any of the above) - and on some difficult to drive speakers bettered a Plinius SA100 MkIII.

Its strong points - neutral-to-warm balance (once run in), excellent PRAT, dynamic and extended. It loses out to the Class A Plinius stuff in terms of smoothness and the last smidgen of resolution - but the PRAT is perhaps superior.

I have to be careful here. One can certainly nit-pick this amp compared with the best. But I am recommending it enthusiastically for how it manages to put soul into the music and gets you playing your whole music collection.

I agree with Sean, you need more than 200 wpc in that big room. A Classe ca300 can be had used around $2000. I find my ca200 to be a good match with my Sonic Frontiers line2se, so a ca300 may work well with your line three. Hard to recommend an amp without knowing the speakers though.

First, a question for Redkiwi. What is "PRAT"?

Also, regarding power requirements, sound levels do not have to be earth-shaking all the way at the other end of the room. 200 - 250 w/channel works fine - especially with a pair of powered subwoofers handling everything below 40Hz. Listening position is about 10-15 feet from the speakers, which are Mirage M-3si's. As hinted above, I am considering 2 200-250 watt amps to vertically bi-amp the speakers which are set up for it. Alternatively, I could do it with 4 channels of a 200watt x 5 channel amp, like the EAD Powermaster 1000 -- which can be had very reasonably for the sound quality offered. What do you all think of that option? (part of the issue is long interconnects in the 2 stero amps vs. long speakerwire with the multi-channel amp). Thoughts, comments, suggestions?