I want to get a Sharp XV-Z9000 or 10000, I was wondering what is the biggest screen I can get where the projector will be optimal. in other words, whats the biggest size I can go where the projection image will look its best. I've read in one review that an 11foot screen is awesome. My Room size is 20ft x 20ft. I want a 16:9 screen. Also, I want to get a Da-Lite screen if possible. If you guys can suggest what my best size could be and what finish the screen should be, that would be wonderful. Thanks