Have been toying with the idea of moving up to a 7.1 from 5.1 after the latest addition of a Sony BD player. I currently run an all Mission speaker set up using M33i's at the front with corresponding centre and a pair of Mission D77S rears. Don't have a massive listening area (5x4m) and was thinking of buying a couple of the Mission Cubes to supplement. Would this be a wise move?? If not the what other options do I have?