I used to work for one of the manufacturers of these boards. Which Stadium are you doing? 32 pixels high sounds about right. They’re usually built in modules that are 16×16 pixels or 8×8 pixels. Most of them are either 24, 32 or 48 pixels tall. The 100 dpi sounds out of place, probably info from an account executive rather than a video person. You can Export an uncompressed AVI from the File/Export menu. Just render an uncompressed Quicktime first and export that. The real trick is working on a Comp that is 4000 pixels wide. Dual monitors are a must. I’ve done some that are 24,000 pixels wide ( 360 degrees arounf a basketball/hockey arena). What a nightmare.