The Student Room Group
I think when i was your age me and my mates did the cinema test, that is invite a couple of girls to the cinema and go from there. Perhaps you can do a role reversal and suggest that you and your friends invite him and his pals to das Kino.
Alternatively, do the blatant obviously thing (but hey least you'll get an answer) and ask one of your friends to go up to one of his friends and ask what he tinks about you. Cheap, possibly but then at your age you aren't expected to be sipping vino in a fancy winebar