If you are wanting a cowhorse prospect, you need to breed to a horse who is built to get in the ground and stop well. A lot of barrel horses are built more like a runner and aren't able to do the sliding stops, etc, very well. They aren't built underneath themselves like a cowhorse would be and are more straight and aren't as low hocked IMO.
To me, SBR Formula One is built more like a cowhorse, but has more flat kneed movement, which allows him to be competitive in other events. I think the main thing that allows him to do so many things is his mind and trainability. I don't think he would be able to compete with the big boys in reining or anything, but maybe I'm wrong!