wow -- I can think of half dozen or more in Straight, but comin' up blank for gay men. There was one guy on here a few years ago that did some awesome fetish photos but I think he closed up shop. Oh wait .. found his site Scrunt's Male BDSM Erotica He was using Verotel for his affiliate program, but I don't know if he still has it active.

I don't know if you'll find anything here: Tom of Finland that has an affiliate program, but worth a look.

Also look around Red Bubble. Again, you might find some of the artists and photographers have websites. You'll have to backtrack a bit probably, or take the artist name and pop it into a search engine. Note: The stuff on this site is for sale, and not for general use unless purchased.