Sorry, I meant LA Boxing. But its the same thing. Their web-site is definitely geared toward someone just looking for a workout. Boxing/kickboxing has become very popular areobic workouts.
A trial membership is a good idea. But if he wants to box he should find a boxing gym, with a real boxing instructor. I've been in boxing gyms and they are much different than the boxing you will find in these big fitness franchises.
If there are no boxing gyms in your area, has your son looked into Mixed-Martial Arts gyms? Its UFC-style fighting, which is a combination of boxing, thai boxing, wrestling, grappling and other styles as well. The one I go to is definitely a no nonsense gym. Guys are there to learn how to defend themselves or to prepare for fights. I've been involved in Martial Arts and boxing for over 20 years, and for me, MMA is the most fun and effective way to train.