This might sound odd but you might consider including p/l volatility, max drawdown, commissions and fees and other metrics as part of your competition. Something that can demonstrate control and discipline. Sharpe ratio? VaR? You see. As another poster mentioned, competitions based on gains alone are almost senseless since the only way to win them will be to take extreme risk, and often winning will be more a matter of luck than usual. Trading like a true successful CTA or fund manager who plays defense as well as offense will not win the competition... Sponsors? Yeah, try IB's and FCM's. Mirus Futures for example. Maybe try the ICE and CME Group. And then you can try Superfund, lol...
Oops I see I hadn't read the OP's post properly -- you're already saying it's not going to be just the highest p/l wins. Good.
Thanks for the posts and comments so far! I will be sure to update the progress as things develope. In the meantime, more posts and comments are encouraged so that we can be sure that this competition is formulated correctly!