Lynn,
It doesn't seem like many folks have tried crossing ground-cover sedum. You did have a splendid collection in Dallas, sounds like you got rid of most of them then? I still have an album seedling you thought was distinct which had just cropped up in your yard, if it ever blooms I may have to try crossing it with one of mine.
Alex,
S. ternatum looks like a fun one to develop, I was unfamiliar with it until you mentioned it here.
-Sol