A client is considering SharePoint 2010 as an information platform on their local intranet (not connected to the internet). One of the main focus points is an advanced discussion forum, including a question-and-answer site similar to Stack Overflow.
I am aware that the out-of-the-box Discussion Forum is extremely underfeatured. After digging through the Microsoft forums, I have come across three main products that are being considered: TOZIT, LightningStorm Tools, and the Jitbit forum for ASP.NET. Besides the technical issues of getting these working on SharePoint 2010 (under investigation; this is NOT my question), these forum systems seem to be quite basic and only a starting point towards a real discussion system or Q&A forum.
My question is, are there any viable alternatives? The platform in question should be extensible and flexible; ie. something we can tune and tweak and customize (for instance, fine-grain permissions are very important to the client).
The reason we are interested in having this work on top of SharePoint is the potential for integration with other information services (ie. connecting to the My Sites newsfeed, connections to documents, etc.).
Any help would be greatly appreciated.