Paul, the main point is the sound level where you're sitting, not necessarily at the farthest reaches of the entire space, and it's possible that the W22s would be adequate for that location. Be that as it may, a setup with M60s and an EP500 would unquestionably be excellent.
I notice that you mention 3 QS8s. Unless there's some compelling reason not to do so, the back surround setup should use two widely separated speakers, not one, so as to allow for the stereo back surround processing which DPLIIx, Logic 7, etc. can do.
