Great idea, Jem
We use a BenQ PB8230 and have had it up for about nine months now. It is bright enough and is reasonably affordable (in the $2,500 to $3000 range). As stated above, though, what it really needs is a swap out lens so that you can go to longer focal lengths and keep it in the booth with you. Right now it's hung from the ceiling about two thirds of the way back from the screen so we have to change lenses and so forth by trying to stand a ladder on the sloped floor and crawling up there. Anyone who knows me knows I am the poster child for ladder accidents so that is no small thing for me.