well, if tama yung nabasa ko, john paul wanted a windows-based forum para sa site nya. either ASP or ASP.NET. so out of the scene na itong PHP or LAMP-based forums.
well, i got my free "non-commercial" version of Community Server for my personal project site. it is already part of the free applications the web hoster offers. if its only the forums you wanted, then it might probably be an overkill na. but for communities as a whole? then...kaya nga tinawag na Community Server.
DNN is also a very good CMS. but the looks of this is very much like PHPNuke. though you can modify the looks by advanced features. 
if john paul has already a hosted site, then maybe there are available web apps or site apps ready to be installed for free for your website just like mine. i installed a non-commercial CS for my personal website.