you didn't mention your budget? with no budget I'd go with the vp150 and qs8's. this should help keep you from wondering 'what if?'.
my room is about 15x10 and I sit about 9ft from the center speaker. I just got the vp100 and m3ti's about 3 weeks ago. I like them so much that I'm sending them back to get the vp150 and m22's. I instantly thought, "wow, these sound so good what if I..."
This is a pain in the neck, and will cost me the return shipping, and cost me much more than I originally planned on spending, but in the long run it should save me some money since I shouldn't have any need/excuse to upgrade the fronts and center now.
I'll be adding the qs8's to the mix within the year. Any reason you are considering the m2 instead of the m22? with your room I'd think they'd be the better choice.
