Well if it possible to scratch a bit funds then certainly the M22 would be nicer. As others have said the Qs4 would be better for surrounds. So if you can get the M22's and Qs4's then do so. If not and you can only scratch togethor enough for M22 fronts or Qs4 surrounds then one possibility would be to get the M2's for fronts Qs4 for surrrounds, and at a later date update your fronts and use the M2 for rear surrounds in a 7.1 system at a later date.

Good luck, Mike