I would look at getting a 2.35 screen and using it in CIH mode as you appear to have more width than height. I wouldn't go with a drop down projector. A false wall with speaker behind it looks like a good idea. Nothing like sound coming directly from the screen. You have enough room to go with speaker wide vs rear surround. I have 7.1 in my HT and I may convert it to 5.1 with height speakers (I'm limited on width).