Hey there!
I'd love to build you a forum site! I would use either PHPBB 3.0 or Joomla with Kunena - Depending on the specific features you would like. Both of these solutions have very powerful content management infrastructures, giving you more control over the site than you could imagine.
I'd work closely with you to iron out exactly how you want this site to work and what kind of features are important to you.
Thanks so much for your consideration,
Kindest Regards, Gareth