Your son should get an "Up to 6'6" Fish, Egg, or Shortboard' or "Up to 6'4" Shortboard" beginner shaping kit. It depends on the type of board your son wants to shape... our 6'6" long kit is designed with extra foam in the surfboard blank to get the feel of shaping without ruining your efforts.
We can ship the kit to your door or you can pick up at our shop if you'd like.