I don't have any specific suggestions beyond what has already been posted (Sneffels' SW Ridge is a really fun climb), but thought I would share a little tool I created that might help you find more options.
If you go to my summit list, you can filter for class and mountain range (among many other variables).
So you can go here: http://www.100summits.com/full-summit-list.html
and then filter class for 3.0 and 3.0 (to only show mountains with class 3 rating), and then filter for San Juan Mountains.
Oh and here's that one that Teresa is mentioning - looks really cool! http://www.100summits.com/full-summit-l ... 5C%22.html