best amp solution for ht and 2 channel

I just ordered an anthem avm20 preamp and now I am looking for an amp(s) to go with it for a 6.1-7.1 system. Initially I thought I would get a 7 channel amp but worried that it would not sounds as sweet in just 2 channel stereo. I've thought about getting 2 3 channel amps to round everything out or perhaps a 2 channel amp for just the mains and then a same brand 5 channel amp for the rest of the speakers but worry that not having the same amp pushing the speakers across the front may not match up well for home theater. Any thoughts on this? perhaps I'm being too paranoid.

setup
avm20 preamp
b&w 604 s3 lcr600 s3 mirage omnipolar fx surrounds
svs 12" sub