Hi Sheila,
Pedal recommendations are a pretty open ended question, as can be seen by vast number of threads and seemingly infinite number of user recommendations in the pedals sub-forum here:
http://www.drummerworld.com/forums/forumdisplay.php?f=27
You'll also notice that the most common advice is to "get your feet on 'em" and get a feel for individual preferance. They are a piece of equipment that if you ask 10 people, you'll get 10 different answers as to what they prefer and why. The very best advice (and the one that the majority of experienced players will give you) is to try out as many as he can.
Pedals are much like sticks....or even shoes, in that the way they feel is truely the best way to judge them. The major hardware manufacturers all offer quality products at various price points and the truth is that most of them are comparable as far as functionality is concerned.....most of them have similar levels of adjustability and durability. In the end it always comes down to the way they feel under foot. I'd advise your son to hit some drum stores and play as many as he can in order to give him the best indication of which pedal "feels" best to him.