You know, I don't really think it's like ordering a pizza. "I want a mistress, someone please send me one with extra pepperoni."
Like any other type of relationship, you need to get to know the person to see if you're the right fit for each other. If you're serious about a BDSM relationship, I suggest you go do some thorough reading in the BDSM forum. There is a ton of information/suggestions in there. The chat rooms might be helpful as well. If you're not serious, then I'm sure you'll find someone to do some BDSM roleplaying with you eventually. Like anything else in life, you get out of it what you put into it, and so far you're not putting in any effort at all.
Good luck with your search!