Have you tried cinemas? They may have old digital projectors knocking about in projection room. I have done this before, but Christies supplied the kit along with a technician, and the biggest issue you may have is real 24p. Yes the light output is very powerful but some of the cheaper units like Sony have naff quality of light and you'll end up building rig to flag the ambient light. They filmed large parts of Oblivion wth DLP projectors and no lights for a global illumination look. What about keying the background in?