Where's the best place(s) in San Francisco to meet a TS. I heard Diva's is pretty low class but have never been there.

Diva's is ok.  Go Thur night or the weekend.  You could go to Power Exchange but some of the TV's and TS's are a bit rough.  When Diva's closes at 2 a.m. there are 15-20 "girls" walking the streets.  Have fun......