For a 70%/30% music/HT mix, whether you'll use multichannel music is possibly the biggest decision point. For example for pure stereo, the surrounds are less important. Whether your receiver has Dolby PLII or Logic 7 to extract surround from stereo is a factor. Whether you'll be getting multichannel SACD and DVD-A discs (and a player) is a factor.
For 70% music, 30% HT, personally I think 7.1 isn't needed. There's essentially no 7.1 music, and not enough 5.1 music!
A 2.1 config with M22 and STF-2 is a great sounding, compact system. Just those alone are better than you'd believe. To add relatively compact and inexpensive surround, add a VP100 center and QS4 surrounds. For music, theoretically direct radiating speakers are better. However the QS4 mounts more easily into space restricted areas than many "box" type speakers. My QS8s sound great for surround music.
