RE: Ultra Sport decisions...
I think the 40 and 60 sized ultra sport kits are identical except for the size. I built the 40 and loaded it up with a YS 63. I really love flying this plane. It's fast, precise and just a joy to fly. Can't speak for the 60 as i have never flown that, but you can't go wrong with either one.
The US40 was my third kit build - it was a little time consuming with all the carving and shaping, but over all it was a fairly simple build.
BTW: RETRACTS ARE A MUST!!!