If you have the option, and are looking for a guest-proof theater, i.e. where all the bits aren't exposed, I'd have the room built and then have another frame built inside of that, on which are mounted (with heavy duty velcro) fabric covered panels. They would be with accoustically transparent for the ones that speakers are behind, and heavier in other places.
Behind that, youc an put all the speakers, amps, sound absorption devices and so forth, so that they are invisible to the users, but very easy to get to. Pop one of the panels off and you can just walk around theater and get to everything easily. As long as you mask all the LEDs and on the equipment back there, the cloth walls will seem completely solid. You can always do the IMAX thing for guests during the theater on sequence and blink the lights back there so that all the equipment shows up for a few moments, while the announcer describes the equipment.
There's a lot to be said for this type of configuration. You end up with a completely smooth inner surface to the theater, so that it just looks like a room with a screen floating at on end, but can have all kinds of ugly sound absorption and difusing stuff behind it, with all the cables and equipment exposed and easy to get to.
The panels can be quite expensive since they are just a wood frame with stretched cloth. You can do something like dark gray with lighter gray accents or something, for good light control and it won't unbalance the color temp by reflecting colored light back onto the screen.
