I have a related question since I'm in a similar small-width environment. The general advice seems to be to have the speakers about 3 feet from the side walls, but if I followed that advice they'd only be 2 feet from each other (8 foot wide space) and basically right on top of the center speaker. My current plan is to have them about 6 inches from the side walls, treat the room and put the screen between them (the screen will about 70 inches wide at that point which is fine since I'm sitting maybe 9 feet away).
If I graduate to an AT screen at some point (not likely given the money), how much in should I push the mains to get some distance from the wall but keep the side-to-side imaging. Also, in terms of treatment, I'm going to do gernally what's recommended by the treatment thread, but are there special concerns related to being so close to the side walls?