Help for a rook...

I currently run a 2 channel system through a Denton AVR2112CI. My mains are B&W CM1's. I am beginning to flesh out my setup to 5.1 channel and I am having trouble with the pre/pro. So the pre would be an amp or set of amps and the pro would be the video processor? I apologize for sounding like a noob, but I am.

So my next purchase will be the HTM2D and shortly after a velodyne Digital Drive PLUS 12". I have been looking at amps for quite some time and with the future upgrade of my mains feel comfortable with what I have settled on. However, is there a large benefit in going with separate amps versus a multichannel?

I know very little about processors so any information or tips would be greatly appreciated. Thank you.