Whether your Onkyo will work will depend on trying it first. Later if your unhappy, you can always get a different receiver or external amp. Some older Onkyos had issues driving the 4ohm m80's, but I think the newer models are more capatible.
Qs8's are the best surrounds available, compared to bookshelf speakers. The point of surrounds is to wrap you in the experience, bookshelfs are more for if your in the sweet spot. Some who listen to multi channel music, prefer a bookshelf for the rears.
Also, depending on how big your room is will determine if you even need 7 speakers, it may be a waste.
