Most AVR's have preouts for each channel, so if you decide you need an extra amp for the m80's, you would use the preouts for the left/right channel to the amp, then hook the 80's to the amp. The other speakers can be driven by the AVR, many of us do it this way.
If your talking about a 5.1 setup, you would not have "rears", but actually "side" surrounds. The Qs8's would be to the "side" of the seating area. "Rear" speakers come into play for a 7.1 setup. A lot depends on where your ditting in relationship to the depth of the room.
Can't you mount the Q's on the ceiling or higher up the wall, that is ideal.
