Nothing personal; but I wouldn't spend my money on a video. Instead I would shoot and talk with all the Cowboys I could and ask about their technique then go and define your own way.
But if you really want to be on that upper edge of competition you can probably fine some stuff in the Cowboy Chronical for sale.
With all that said, you may ignor my comments because I shoot in the middle of pack and don't intend to get much better. I have a great time shooting double-duelist and plan on going to gunfighter eventually.