WPMU forum points rewards system

Hi guys!

We'd like to implement a similar system as you have in your forum on our entrepreneur blog. To be able to assign points to our contributor's contributions (post publication) according to the quality and amount of published posts, give them family (I'm the child of Thor on WPMU now lol :smiley: and as they climb up the ladder, give them rewards, etc.

We already have bbpress installed, but it's more a publishing post rating thing.
What can you suggest?