Sounds like fun - but should make it part of the rules to post a minimum of a weekly progress pic of the plants starting from first sign of hooking -- figure that would ensure everyone is using this years seed and not a plant they just happened to overwinter ! (Plus we'd all be able to keep tabs on everyone's progress !)
Or maybe make it a Home Depot, Walmart, or Lowes bought seedling of a variety they always carry (ie. Jalapeno, etc.) and see who can take it and make the most out of it by the end of the season ! (figure that way it's kind of like same seed stock without the need to organize a mailing)