Look for advices

Dear developpers,

I’m in the willing to use wordpress as the new general message tool for my society. Today, most of our users use an address like all@society.com to inform everybody.

I’d like to use WP instead but, by the way, adding more than this looking like CMS features :
Everybody here belongs to a unit. Each unit could get a category, and all users from a unit should get the right to post in this category. Other users who want to post in a category that is not their should be moderate by one particular user from the destination category/unit. This same user should be able to delete message from it’s own category.

To sum up :
o General rights :
– everybody can read post
– all user can edit his own post
– a superuser can do everything
o Unit/category rights :
– all user from one unit can create post in his category
– one user from unit can delete/edit all the category posts
– all posts from users outside the unit should be moderated

One user can belong to different units.

Data concerning users membership is in a SQL DB repository but links or synchronisation with WP could be considerated.

Could you tell me if plug-in exist to accomplish this (db connectors, userextra) ? Which one is the nearest to be modify ?

Sorry I didn’t read all the FORUM for those informations, but it’s now look impossible (to much messages but it’s a sign of a good popularity).

Elpipo,