Cover Eaten from the Inside. The solos in that are pretty cool. All kidding aside, people react different to local/talent show/whatever type musical performances than they do big name tours. They most likely won't care if you went as far as to dry hump your guitar. Most will pretty much be satisfied as long as the song is completed (this is based on my experiences alone so don't expect that to always apply). I once performed in a talent show with a couple friends. We made an original composition and performed in front of a few hundred people. It sucked, it was trash, no rhythm what-so-ever, our timing was the worst part and the "solo" that we had conjured up was total trash as well. We were easily the worst performance in every way. But would you believe it if I said we were the only ones that got a standing ovation? If you're looking to impress people that's fine, take this as an opportunity to challenge yourself, but keep it reasonable as the studio is typically where you really challenge yourself and performances are for things you've already mastered. I'd say shoot for the original song but keep a cover as a backup in case the song doesn't pan out. All the same, best of luck to you.