Here's your answer.
Don't buy a rear projection unit, or an LCD, or a plasma. Buy a front projection unit. You can easily project a 110" picture, and it's as bright as you'll ever want. The picture quality will simply blow away anything you've ever seen. You'll never be able to look at anything else ever again. It supports all HD formats, including 1080i.
Here's a resource site:
Projector Central
Here's the unit I love:
Sanyo Z3