"do you know of any other DLP that is as good as the Dom20 that does have a short throw?"
Not quite, but almost as good as the 20 (IMHO), you could try the NEC HT1000 or newer HT1100. Both are 4:3 1024 x 768 projectors that can be 'forced' into pure 16:9 mode, so they will behave just like a dedicated 16:9 pj ALA the Domino 20.
From approx 11ft away, you can project up to a 7ft wide image. The only drawback of the above two NECs is the very faint light spill above/below the 16:9 image where the unused portion of the DMD array is still projecting a minimal amount of light. I only barely notice it during very very dark scenes if I look for it.
The NEC does get good reviews, and is short throw, so is worth a look IMHO.
Gary.