Help me pick a power amp

You might want to look at a Parasound HCA 750 or 1000. They also can be strapped into mono unlike the Adcom's and that allows you an upgrade path.

These are readily available on ebay: (http://cgi.ebay.com/David-Hafler-Model-DH-220-stereo-power-amplifier-220_W0QQitemZ160392533002QQcmdZViewItemQQptZVintage_Electronics_R2?hash=item255823d40a), and sound much more like music than most of what's out there, in your price range. They can be strapped mono, and there are companies that still offer upgrades, should you desire to go that route in the future. The one in the listing is either a later model, or has had a number of caps replaced with polypropylenes(the blue ones), that the early models didn't have. A VERY conservative 110 W into 8 Ohms(continuous), and can drive a 2 Ohm load without any problems.

Maybe widen your search to older NAD amps, like the 2400. And like others said, put Adcom's on your list too, maybe Rotels. "Opportunity" in that price range can be key.....

I've had many B&K amps and you can't go wrong with them - especially in your budget range. I've also had several Parasound amps and agree with Tommy - the HCA1000 is a good option and can be found in your range. I find the B&K amps to be a little more natural sounding, primarily because the Parasounds have a little bit of punchiness in the bass, although this characteristic is attractive with the right speakers.

The build quality of both B&K and Parasound is fantastic.

Here's what a few had to say about the Hafler DH-200, the model prior to the 220(which had more power and some other audible improvements): (http://www.audioreview.com/cat/amplification/amplifiers/hafler/dh-200/PRD_115808_1583crx.aspx) There are some 220 reviews included. A number of the posters have owned NAD, Adcom, Bryston, etc and noted their preferences.