Recommendations for a "summer" amp?


Living in a hot southern climate I'm considering acquiring a 2nd amplifier for summertime use as a backup to my Pass Labs amp which runs quite warm. Solid state, cool-running, fairly recent vintage (don't want to invest in service) with a used price somewhere below $800. I had a good candidate in storage but I gave it to my brother so I need some recommendations. My system is comprised of an ARC tube pre and B&W Matrix 800 series speakers.
abrew19
The Luminance Audio KST-150. It is a high speed, high bandwidth mosfet amp. It runs very efficient like a digital amp and is cool to the touch, but its sound will blow any digital amp out of the water.

In fact you will probably not want to put your Pass amp back in once hearing it, a true giant killer. It needs a week of break-in, more so than the typical new amp.

http://www.luminanceaudio.com/
My "summer amp" is the Marantz AVR in my HT system. The sound quality is good enough considering that the noisy AC unit is running full blast anyway, which trumps serious listening.
I would suggest any of the upper-tier Parasound amps from the 2-channel HCA series: HCA-3500, HCA-2200II, HCA-1500 (in descending order of wattage/power). Between 10 and 15 years old; should range in price, used, from ~$800 (HCA-3500) to ~$350 (HCA-1500). They're all rated for 4 ohms; the 2200II is rated down to 2 ohms. The 3500 and 2200II are probably the ones you want for those speakers.