Ro, a little more about positioning the QS4s. The general idea for side surrounds in a 5.1 system is to have them about 2-3' above ear level and slightly behind the listening position. Since you're going to be sitting very close to the back wall it may not be possible to put them much behind you if they're on the side walls, but about a foot away from the back wall may work well. Possibly a bit better in your case would be to mount them on the back wall, but widely separated to about a foot away from the side walls. You might temporarily try both arrangements to see if you like one better.
