I need a SPECIFIC PVP Plugin

Hiya! I'm getting my server up and ready, and I've decided something: People complain when PVP is disabled, but they also complain when it isn't!

So I'm looking for a plugin that lets two people AGREE on PVP with a command such as /pvpagree (playername) or something like that. Can anyone name a plugin? (or two or three)

Thanks!