You should feel very comfortable going with the VP100. A lot of folks around here are on a matching front three kick, which is theoretically optimal. Functionally, however, it is often non-optimal, nor is it always the most aesthetic set up. Indeed, it looks a little different than most standard set-ups that folks have grown accustomed to looking at, with a vertical Left and Right and a horizontal Center.
The difference going from a 2.0 to a 3.0 system, with a VP100 laid horizontally will be significant. I don't think you'll find many folks recommending you get a third M22 and laying it on its side, though. If the horizontal orientation is a necessity, go with the VP100 and don't look back.
In re: wireless surrounds - don't let the fear of running wires scare you off. Know that wireless speakers need to be plugged into the wall to work, so wires are unavoidable.
You can buy white (or any other color) speaker wire and tack it to the baseboard just like the cable TV line without it looking bad. There is also flat wire that you can buy (available from Axiom or from third parties). I used a flat wire product that was no thicker than a business card. When laid flat on the wall using a spray on glue compound, after applying a little feathered spackle and a paint job, the wires were indetectable except on very close inspection. This helps with the eyesore of wires on the wall.
Surround sound might be one of the biggest improvements in the whole "movie sound" experience, for me at least. If the sound is immersive, full and rich, it is much easier to be drawn into the picture. In fact, given a choice between a high def 100" screen with wimpy, stereo sound, and a 42" standard def screen and a kickin' 5.1 sound system, I choose the 5.1 every time.
I'd got with some QS8s - they are an incomparable speaker - I think they might be Axiom's best. Other companies make great floor standers and bookshelf speakers - some that migth even sound better than Axiom. NOBODY makes surround speakers that perform as well as the QS8s.
