Is this being coded or evented? You said "coded" in the OP, but for some reason the context makes it seem like you use the terms interchangeably.
If you don't have a coder, and would be interested, I'm actually working on a script for this exact sort of thing. I have no where near as much in terms of building capabilities, and would be happy to develop it for this instead.
Of course, if you're coding it yourself/having someone else do it already that's perfectly OK.
Wait, I thought you were making a full-on GMod Tower sort of thing. I guess my offer still stands if you wanted to make it that.