Integration in an existing site...

Hello,

I've been asked to search for a forum that can easily be integrated in an existing site. It goes a little further than just adjusting the templates to fit the look'n'feel of the site, but should have the following stuff:

- There is already a user system, and users already log in to the site. These users should be used to authorize access to view/post new topics. Administrators or moderators should use the same system, or some other login method...
- There should be a couple of stand alone forums ("general discussion areas"), but the site also has "articles", and with every article, a discussion thread should be created and displayed together with the article, and also accessible through the forum. It boils down to the view of one thread/discussion with every article, and the automatic creation of new threads as articles are created. I can add code to the creation logic of an article, to manipulate the forum databases.

I'm skilled at PHP, and hacking the code of the existing site and the punBB code to a certain level is no problem, but before choosing a forum to start from and start the integration, it would be nice to have some pointers and user opinions on the changes above. I guess that the user integration should be fairly easy, as long as I can change all the lookups for the user data to return data from the correct tables/classes/objects in the existing site. The automatic   thread creation and the inclusion of only that thread in the page displaying the article, might give me some more trouble .

Any pointers (you don't have to give details, pointers to threads and pages are enough, I'm not lazy or not willing to search, but I'm just short on time ).

Rgds,
Wonko