If you don't mind some self-pimpage, I wrote a fic called Gentleness (http://eagle-of-idiocy.livejournal.com/34056.html) a while ago that I think fits what you're asking for. It's rather short, but it's got bottom!Jim and a gentle, sweet Spock, and I think you might like it. :D

If I run into more stories, with either Spock or Bones in them, I'll toss them your way!