Red, we have just about the same set up, room, equipment, etc.. Go with QS8's, As you already have the best of the rest, why short change yourself on the surrounds ?
As for the rears, go with another set of QS8's.. Think about it.. If you were the one sitting in the back of your theater room (didn't arrive in time to score one of the sweet spot seats), would you want those rear effects coming right at the back of your head ? No way.. With the Eights, you get the same 'rear' effect, without the sound becoming too directional, eh..
Believe me, I went round and round on this one myself.. A pair of VP100's, or one VP150, etc.. Just too much trouble.. So much easier to hang a couple Eights and forgettaboutit :>
Besides, it's a win win dude.. You get really great speakers, for both music and movies, and in my opinon, they look much better on the side and back walls then than the VP series.. Blend with windows, pictures, etc.. Look more Movie Theater like, know what I mean ?


LFE ! The rest is just details..