Yeah sun polyps don't need much light at all ... if any! My LFS
had a few, but I was advised that because of the feeding routine it was a more difficult coral to keep.
I skipped over it and went with some blue/purple shrooms
and absolutely love them.
I recently setup my Nano and aquired some Green Star Polyps, some Neon Green Zoo's and a Ricordea shroom. They are all very nice corals but require higher lighting! If you place the Ricordea high enough in the tank you may be able to get away with those as well as some bullseye shrooms
! I put 2 Bullseye in my 29 gal
at the very top of the rock under 2 20 watt bulbs and they are doing great!!!