This is not my area of expertise, but, I would think local newpapers. On your site also put a link for people that want to sell their pics, either of themselves or if they own exclusives. I don't know what the protocol is with recruiting at strip clubs and the like, they probably wouldn't like that though.
Oh...I was just ICQ'd from a vet here at this board, wiZd0m. I asked him and he says he buys at Matrix and from David Lace. I'm assuming that is exclusive content not models you can photograph yourself though.
Good luck.
