Toby.. Here's a thought.. What's on the other side of the wall that your couch is against ? Would it be possible to mount the projector on the other side, with an opening into the viewing room ? You could put a cabinet around it, or mount it into one if one already exists, or just set it on a shelf ? The work involved would be nothing really.. Two layers of drywall, a little sill and casing work, and shes a done deal..
Shoot, even if the other side is the out doors, you could box it all in, making it weather tight, etc.. There are vents to match every need in building supplies these days..
