2 subs is much easier to integrate as long as everything is square. It also provides a much better balance in the sound.
I would also go m80's and 2 ep500's.
Why 2 centers? Your room isn't that wide, and it would probly be a waste. The 120 is already 27.5 inches wide, and will disperse much wider then that.
I also recommend 2 pairs of surrounds, and see if you can do with qs4's over 8's to save even more. Email axiom and see what they recommend aswell, because they made the speakers.
Good luck with purchase,
Sheep