Howdy,
Seems Rio has hooked you up.. I hope that you have the required guns, which are blackpowder or cartridge guns of the opentop design. These can be Pattersons, Walkers, Dragoons all the way to the 1872 Opentop. Main match guns are the only real requirement, as the pocket pistols, while cool, don't really make you a Rider of the Storm..
Adios,