Dear poster,
I think you need to be more prepared, check the dedicated sites and try to glean what is happening in wider world of home entertainment, go to following link,
AVS | Home Theater Discussions And Reviews
Explore forums, especially their home theater builds, try to get inspiration, after you have educated yourself then ask questions according to your own specific requirement, anyway If I had your budget I would not go to projector route, I would stick to HDTV, and build a nice and reasonable system around that.
Faisal