I want to recommend a coach we've worked with in the past. His name is Jeff Holly. He comes from Southern California and is now living in the Portland, OR area.
If your son needs personal instruction, in any phase of the game, this is THE guy, in my opinion.
We met Jeff about ten years ago and traveled from IL to CA several times to work out with Jeff. Now he's in OR and we recently Skyped a lesson with him. He's the greatest.
I won't carry on too much here but if you want more information, message me and I'll tell you all about him.