I just ordered an optoma hd20 (should be here next week). Now after obsessing about the projector for far too long, it's time to start obesessing about the screen. This is my first projector and I am not sure about which direction to go with the screen. There will some ambient light as it will be in my living room. I have the flexibility to mount the projector as far from the screen as I need to. What is the price to paint a screen vs buying a screen that is comparable? Any recommendations on the paint to use? I would like 100 inch screen, give or take a few inches.