Not much TV advice your you I'm afraid. I'm still waiting for my 46" Toshiba DLP to die. It's embarrassingly big for this day and age but it's still every bit as clear as the day I bought it. I'm certainly getting my moneys worth.
I do think you might max out at 42" up in the corner though. Anything else might just look too big aesthetically, if that is an issue.
On a side note, I won a free X-10 camera years ago when I was rigging up my old house with a bunch of X-10 stuff just for fun. I used it at the front door as well but I also had rigged up an X-10 controlled Nerf gun to it. It was mounted on the camera itself so you could aim it by panning the camera. I was able to make some tiny crosshairs on the lens out of cutting tiny strips of black tape and aligned them by firing against an old piece of plywood and noting where they hit on my screen image. Took a while to get right but it was accurate enough considering it was generally only 4 feet or so from people.
I'm thinking this sounds like something you need.
