Thanks for the great info. I wore gel shorts when I first started riding, but now they just seem too thick. I actually wore a pair of "tri-shorts" the other day on a 25 mile ride. I don't know if you are aware or not but the "tri-shorts" have an extremely minimal pad. It's more like just a few extra layers of the lycra material. But what surprised me, is that my butt or anything else couldn't really tell the difference. What I mean to say is, is after I got home nothing was sore. About a month ago I purchased a Selle Italia and once my butt conditioned to that, it hasn't been sore once.
But due to your info, I will look into the castelli shorts. I have seen them several times in the Colorado Cyclist catalog and of course online. The look pretty cool. Hopefully they will fit well also.

Thanks again,
Karen