Okay Dan, as sushi pointed out, some amps have provisions for bridging two of their channels into one, which would in fact give you double the power. Since the 7000 doesn't have provision for that, if that was a major reason for buying it, don't.
Bi-amping, which could be done with the M80s since they have two separate sets of terminals to the high and low drivers, doesn't double the power. The way that you would have to do it, without an external crossover, would have minimal if any benefit. Each amp channel would still have to carry the full range signal and the power of only one amp would be available to a driver, not two. Don't bother.
