Billy, the 7500 will be great.

I'm a bit confused though by the statement that bi-amping could cause problems. I suspect the recommendation refers to active bi-amping, which co-incides with the Vista (and reQuest) manual advising against that method.

The manual, however, does go into detail (pages 8 and 9) defining wiring methods for both horizontal and vertical passive bi-amping. I personnally run vertical bi-amping.