Here's another guy you might want to check out:
Doug Mills Horsemanship - Home
He's not too far from where I live and although I've not watched the DVDs, I know that he's good. He's won many colt start competitions.
Then there's also this guy:
Jonathan Field Horsemanship - Horsemanship Dvds - Natural Horsemanship
I know him personally and he's very good. I've watched the DVDs and the content is good but the production quality is not as good as Parelli.