Custom WordPress user role "groupings"

I need a WordPress plugin that will create a new/separate group of user roles: keymaster, moderator, participant, spectator, blocked. Role capabilities should match bbPress' existing parameters: [login to view URL] However, for the purposes of this plugin what bbPress considers forums are in fact "categories", "replies" are "comments" and "topics" are "posts" Feel free to use existing code from the bbPress plugin.