If you get a chance to listen to the ATI amps, you might be surprised at how good they can be. You could go for an AT 1505 for 5 channel, or pick up a model with less channels and get a good stereo amp of whatever make you like for the mains. The 1505s are bullet proof and I used one for several years in my AV system for the surrounds. You can probably pick one up for $500 or so used.
Other modestly priced but very decent sounding multichannel amps can be had from Adcom and Rotel.
Other modestly priced but very decent sounding multichannel amps can be had from Adcom and Rotel.