I got a somewhat similar setup last week - Denon 3802 with M60s for the front, VP 150 for the center and QS8s for the surrounds along with a EP175 (I toyed with the idea of a Hsu VTF for a while, but eventualy decided to go with an Axiom for its musicality); My room is similarly sized - 25 feet X 14 feet with a vaulted ceiling but with carpet. The system sounds nice but does not produce as much output as I thought it would (based on a lot of posts in these forums), especially when watching DVD movies. The output with music CD's is appreciably higher. I suppose I should have gone for the larger sub. The QS8s are good but a couple of times when listening to music, I have been rattled by some resonance - kind of a buzzing noise that is not part of the recording but is being generated by the speakers. However, the sound from the other speakers (I tried running 5 channel stereo and tested repeatedly) was clean. I am not sure if this is present only in the two QS8s that I got (FO) or is a general issue with the 8s. I would suggest that you try them out and if not happy, get a pair of bookshelves instead.
PS: I got a pair of the QSS8 stands to get around problems with speaker placement. The stands (not made of real hard wood incidentally) look rather tacky with a thin coating of vinyl (note to Axiom: A pair of elegant but strong Aluminum stands would considerably enhance the QS8s). If you are planning to get stands, try to get one of the alloy stands that can accommodate the QS8s.
