If you know what you're looking for, you can post your requirements on elance.com and have several designers bid on the work for you. I do web design, but have never built a site for the adult industry. If you need some pointers or advice in what to look for, PM me.
I don't know the designer that Luv4Lust is recommending, but have a look at L4L's site and see if it's the kind of quality you're looking for. Portfolio is key.