Dean. A pro amp is what the musicians use. Crown is one example, Behringer another. The Behringer EP2500 puts out 800w/channel at a cost of around $350 new. Now, a lot of audio guys don't think the 2500 is clean enough for powering mains, but even if you go with more reputable pro amp suppliers at double the cost, it is still a lot cheaper than consumer grade separate amps.
There are some good discussions on avsforum about pro amps. The biggest downside is that some of these amps can have noisy fans cooling them that need to be moded for home use.