If you're going to be sitting 20' back, you really are going to want the M60ti's. You'll have to push those little M22's pretty hard to give you a real thrilling movie experience if you're sitting that far back. The M60's will be perfect.
I'd also put the extra money into a VTF-3 subwoofer, rather than the extra channels in the rear. Stick with 5.1 and a really kick butt sub. You're room isn't all that large, and if you're sitting 20' back in a 24' room, the added 2 channels aren't going to wow you like a really good sub will.
M60ti
VP150
QS8
Hsu VTF-3
That's my recomendation.
Enjoy you're new gear!
