In my opinion the best place to start in an honest assesment of your sons current skill level. If he is an average to a bit better than average player you may want to consider a club such as the stampede or havoc or a similar club..if you think he is ready to play at a high level of competition maybe consider clubs like the express or team 91. Choose wisely for it is a big commitment both financially and time wise. These teams also vary greatly in price..but it has been my experience that you get what you pay for.
One more point worth mentioning...many travel clubs pull from specific towns or regions of the island..ask around at your town games.