This request seems a little unusual. Most of the girls that have consistantly good ratings as GFE's are going to be good no matter your age or appearance. The reality is that they are being paid to spend time with us. Looks and age are of no difference to them. The vast majority are tinkled if your freshly showered, sober, polite, fun and normal in your interaction and even more bonus points if your complimentary. I would venture to say most even prefer older men for some of those reasons. It would even be foolish to ask if they don't mind because I can't think of any that would say oh no I only see good looking guys between 18-30 with only 15% body fat. In fact if you looked nationally there are a number of young indipendents who will only see men over 40. Just relax. Pick a girl with lots of reviews and spend some time. Clean and polite go a real long way. If I had to worry about providers being attracted to me I would go nuts. I'm overwieght over 10 and bear no resemblence to Tom Cruise.
Have fun and pretend your a stud.