Cloud 9 Walkers are probably some of my most favorite breeder/trainer out there. They do such amazing work with their horses, all of it natural and can make any gaited horses with a horrible gait as smooth as silk. Just check out some of their videos here: Bluezfool's Channel - YouTube
And here is their site: Tennessee Walking Horses -- CLOUD 9 WALKERS - Tennessee Walking Horses For Sale
They are located in Texas.