Which yii user management modules?
I've just been playing with yii-user-management (0.8rc5 at the time of writing this). They have just added a load of heavy features to this project: avatar, membership, profile, role, usergroup, friendship, messages, registration and user.
Unfortunately the code base is not as stable as it could be, which is why it's still an RC. You will have to be prepared to get your hands dirty with reporting errors to the developers, but this is definitely a project to watch for the future.
yii-user only has options to be a user or an admin. Yii-rights actually allows new roles to be defined. I would go with yii-rights. It's been continually updated every couple of months for a year now.