Hi,

I'm developing a group-commenting system (a light-weight forum) where
1) supports 100's of forums, one at each node
2) has a twitter-like Web2.0 look and feel - short messages, profile picture, AJAX expand/collapse of replies
3) use node-level access control so that users can only see the comments for the forums they belong to
4) supports email notification (daily/weekly digest or instant notification), so that a user gets notified when someone posts
5) Moderation by moderators per forum would be nice to have

Which are the best modules to use as a starting point and customize if required - is there a Commenting module to achieve this?

thanks
kbellare