Best forum to be integrated with Yii

Hello community,

I am planning a little website which will be based on the great Yii framework. Since I also will need a forum I am looking for a forum-script which will best fit with the Yii environment. Currently I am thinking about using the Yii User and rights extensions. So it would be great if the forum´s usermanagement would allow to use these as a basis.

Thanks a lot for any of your recommendations