Have you checked
http://www.smcrevenue.com/
With sites liek
http://www.privatetransexual.com and
http://www.shemale-club.com they are way up there. They have been in business for 8+ years and are up there with the review sites as well (I always check that before I push, get some site facts)
Plus mainly American Shemales which is a BIG plus in that niche.
Try them you won't be sorry
Sebastian