Previously(a few months back), there was always a skinny guy who used to host the customers at Nice Guys and he would always guide you on which boy was good at certain aspects...personaly, I like the new ones with no experience... and while the owner was there, he didn't interfere at all except to gently intimidate the boys into his style of performance. Then recently, the owner started doing the hosting himself and failed miserably by all accounts. Even though I like to pick the boys based upon first impressions rather than someone else's opinion, I usually ask who they recommend to stall for time while scanning the faces.
Another possibility at Nice Guys is to wait till there are no customers viewing the boys and a lot of the old hands will mill around outside where upon you can chat to them and ask them for the name of the individuals who will do what you desire....then go inside and ask for that boy.