You've got to find amp channels to drive all of those speakers anyway, and one reason that multichannel amps like the 7700 have become so popular is the simplicity - the alternative (buying an assortment of one, two, and three channel amps to drive the five or seven speakers required for a surround setup) takes up more shelf space and can often cost more (since a single amp can be more economical to build on a dollar per channel basis). Your mains are going to need a substantial amp to drive them, and the center is likely to be similarly demanding. I'd go with the 7700 to drive everything.