Alright, since no one replied, I'm going to tell what's possible. If you have ever created the plugin where at the end when there is two men left (one on each team) and they attack their knives on the wall and there's a menu and if they both agree, they can only knife right?
Well this is almost like this, only differences is that the menu show up automatically, and if they both agree they switch to boxing gloves instead of knives. I'm sure someone could make a model for it. It's really simple, this isn't rocket science. (Sorry if I was a bit rude there)
(Don't say "If this is really simple why won't you do it yourself?", it's because I don't know how to create the simplest plugin in the world)