Douglais-
Take it from somebody who has been to a lot of biker rallies as a vendor; there are a host of large biker rallies you should try first before Sturgis or Daytona. It will save you money and give you a better idea of what the market is. A lot of states have "Too Poor for Sturgis" rallies, Laconia in NH, The Carlyle rally in PA, to name just a few. And yeah, the helmets with horns would more than likely sell well.