Best place to start are the main agencies that specialize in PS providers. Trystagency, PC, AIA. There are also a number of assistants who have their own lists, you can probably find some of them by doing a search of this foru,

Lke most of the real good stuff here you need to be a VIP member.  Then the Provider Search form will let you select all sorts of characteristics.  There's a Porn Star cehcbox

I always use Tryst and Eros.  I toyed with the idea of registering on Alluring something Arrangements.   I can't remember the name now.  Damn getting old sucks!