D.D.
We put our kindergartener in wrestling last year. He loved it. He placed 1st, 2nd and 3rd in almost every event. It is a big commitment, but it is such an individual sport. He grew so much confidence, and it really help him focus more at school.
It is long tournaments, but you get to know the other players and learn their strength and weakness. You get to know the other parents around you and start rooting for their kids too.
I would try it, especially if he has the desire. Good Luck.