If they had some decent striking and kicking ability from their previous training, I would actually recomend 1 to 2 years of Wing Chun (given how quick they pick things up) to give them a crash course on sticking and trapping and then run from the style as fast as they can.
From there I would say go to Hsing-I to get some power.
Then go deeper into an art who’s technique and aproach fits your style.
lol someones kinda biiiiaased 
Well, that’s what I would say if we had to keep it to Kung Fu.
Though I’d say get our kid into a grammer school or HS wrestling program, because you can’t talk martial arts without it. Looking back, I wish my HS had wrestling … would be saving me a lot of trouble now, if I had that type of stuff hard wired into my muscle memory.
if you are still in high school, wrestling is fun as well as valuable in teaching you the basics of fighting sind most of the time fights end up on the ground anyway.this will teach you how to take someone down and twist em up, the next step after wrestling would probably be judo,shuai chiao, or bjj, these are more complete and advanced forms of wrestling, then to balance it out you could learn a little tae kwon, or karate, boxing or any other external art, too many to list, then if you really want to reach the pinnacle, learn the internal arts such as ba gua hsing i and tai chi these internal arts break it all down into a complete scientifical complex system, and is hard to master. many people will bash internal martial arts because they do not know. thats the basic hierarchy of martial arts in my opinion.
hierarchy based on what?
based on my opinion cumquat, cant you read smartguy? they only stand out as the last words on my entry…or did your a.d.d. interfere with that.
lol dude…
did u just call me a cumquat?
what the **** is cumquat?
So you have knowledge in the kicking and punching area. You will need locking and throwing knowledge to make yourself complete. So the answer is very simple.
hahahahaah! the world is a cumquat.