If you can find one, look for the a300.2. The ".2" is the best design. It runs cooler and more efficiently. I personally have an A200 and it is AWESOME. They are highly underrated and as long as you have a crossover, you can't go wrong. They are the cleanest of all amplifiers save Zapco and just a few others. THD is .02% @ 4ohms. My brother-in-law had 3 running his entire system and 1 Kicker C-12 sounded like 2 15's. Granted, that was several years ago, but still.
Im selling my a300 right now on ebay and you can check out my thread in amplifiers. Its the only one on ebay and its the white art versian. I also have a a600.2 but thats not for sale