I'm trying to decide on my first proj. but I need help with a couple questions first. My finished ceiling height is only 6'8" tall. I want to mount a 16:9 screen on wall all the way up to ceiling if possible. Do I need a proj. with lens shift to make this work? I don't want to use keystone correction. I don't want underside of proj. below 6' height. Is 8" enough height to make this work? I sure could use some advice.