I have an ESX Q604 (discontinued -- avoid newer ESX amps like the plague!) for the four main channels and an Infinity 102a (again, I believe this is discontinued) which is bridged to put 200W into the subwoofer (which is a Hsu in their prefab cylindrical enclosure -- takes a lot of space but cheap and sounds *beautiful*).

The way I picked the amps was simple; I went to www.mmxpress.com and bought whatever they recommended and had for cheap. I haven't bought from them in a while but it's been my experience in two Empeg installs of my own, one install into a friend's car, and various other car audio tinkering that MMXpress sells very good stuff at very good prices; it is hard to go wrong if you buy from them.