Yes, John LaTourette is in Medford. I stopped by his school back when I was a TKD green belt and I was amazed at the speed and power of one of his instructors who worked with me. After being in Kenpo for a few years now, I'm not as impressed with what I saw, but it wasn't bad, that's for sure. I have some of his videos and he's definitely a different kind of instructor, kinda loud and nasty.
Another good school in the Medford area is Chip Wright's Champion Karate. He's one of Chuck Norris' blackbelts. Actually he is/was Chuck's stunt double for Walker Texas Ranger. That's usually him you see whenever Walker is doing anything athletic. Anyway, Chip is an excellent instructor, a champion-level fighter and a good person. It's Tang soo do, not kenpo, but a good school nonetheless.