There is even a sub-index for porn stars. So you at least you have an assurance that they really do know how to perform - and for a long time!!
Japan used also to have a pink guide with listings for almost all the gay bars and their specialities - for young guys who like older, SM, chubbies, chubbies who like slim, etc. Not sure if it is still published. And when I'd go into a bar with a Japanese friend, the mamasan would eventually lean over and ask, "Are you top or bottom?" He was not being nosey, merely making sure that he would then sit you next to someone who was the opposite of you! It is all so well organised!