On Join Classes

NOTE: I know this may already be a plugin, if so, make sure to give me a link.

Hi, I'm looking for a plugin that gives players an option when they join a server what group they want to join ( in my case, my server gives users an option to be a: cop, civilian, and a gangster, ) I would like it to open a menu of some sort and they click the option they want ( there will need to be a description of the group they are going to join ). Upon joining a certain group, this player will be given a set of permissions and there will need to be commands executed when they join the group.

I would also like it if the players would be able to change groups whenever they feel ( of course with a cooldown time ) but upon doing this, all of their player data from when they were in the other group will be deleted and they will have to start over.

EXTRA NOTE: This plugin will be running on a modded server ( if it gets created ) so if you can find a mod to comply with the plugin, that would be excellent.