Well I think the walls are going to work for the surrounds with the exception of the right (?) surround. JC said they don't all need to be at the same height, as long as you adjust the volume in the setup to equalize the db levels.
The right surround will be installed on the ceiling of the "dining room", it is really just one big room, but that 1000 cu ft piece of to the right side has a 10 ft rather than a 12 foot ceiling so I was thinking about mounting that one on the ceiling and angling down (no testing there, just have to bank on the "forgiveness" of the QS8s), while putting the rear surrounds and left surround somewhat lower on the walls to conform more to an idealized Dolby setup, those are the ones I would experiment with speaker height.
