I've never had or seen problems with consulting such issues at a place like vbulletin.org. I honestly think this is the best place for it, that or vBulletin.com.. but, whatever.
Another great forum is Sitepoint, which I'm currently adoring since there is so much useful knowledge spread throughout the forum, coming from very brilliant coders.
There is the "Building communities" forum at Sitepoint you may want to look into, if you haven't already:
http://www.sitepointforums.com/forum...php?forumid=71
If this doesn't suit your needs still.. and you can't find it through google, perhaps you ought to create such a forum yourself.