We're building an addition to our house and I've wired for 7.1 in the walls. I'm currently using a 5.1 Kenwood receiver and am in the market for something (7 channel powered receiver) to power these 7 speakers. I'm thinking of expanding my search to include 5 and 6 channel powered receivers with pre-outs and getting external amplification. However, it seems to me that if I were to go with a 5 channel receiver (i.e. HK 520) and an external amp I'd want that amp to power the two main front channels and NOT the rear surrounds. But I'm NOT under the impression that the amps in the receiver are "assignable" so that I can tell them which channels to power. Most likely the external amp/s would be of higher quality than the receivers amps and I would want those for the mains for music listening. Am I thinking right here? Missing something? Thanks.