tezelle,
If you're interested more in good "environmental" sound rather than good "serious listening" sound (i.e. sitting in the sweet spot and paying full attention to the music), I think wall mounted M2s would be the ideal speaker, especially if you already have a subwoofer. If your receiver can drive two pairs of speakers, I'd recommend buying 4 M2s and mounting them near the 4 corners of the room.
I wouldn't recommend mounting them too high on the walls, though, as almost any speaker suffers from diminished detail when you listen off axis.
