He should be someone with experience in Tourette's. Behavior mod can help with some of the minor tics but repressing them can cause some additional problems. I haven't heard of supplements helping but if you can find a doctor who understands that aspect, it might be worth a shot.
http://www.schoolbehavior.com/conditions_ts.htm has some good information on tourette's.
Read up on the disorder, get more information. :)