apology accepted, I had my head in code all day so wasnt really in an explanitary mood.
THe main problem with a mac is the emulators really. Some work quite well for macs but not all.
The projector Idea would work but from all the projectors I have seen their images arent clear enough and can be quite washy, they are also subject to surrounding light washing the image so it means you need relative darkness. My friend has a projector and I played a few PS2 games on it but in the end we swtched back to his TV and kept the projector for fight night and the football

I guess another option which would reduce the footprint and other over heads making the machine even more accessible would be to use a Laptop as the computer and connect it to a flat panel LCD screen.
Your concept has a lot of merit and i would like to offer what advice I can. One cool thing besides voice software for it would be a trackball on the edge of the table used as the mouse.
let me know if there is any other advice I can help with