Let's break down the purely technical side of this a little further.
Tracking information--"agent" data and the state of various challenges--is going to require a database to be glued into the main site using PHP or similar. If we already have the database, it should be possible to patch in code that activates and deactivates the auxilliary websites automatically based on whatever criteria we set (assuming an Apache-compatible server, modifying an .htaccess file is probably the easiest way). It may be possible to do this with a CMS such as Joomla! or Drupal, but that might also be more trouble than it's worth. (On the gripping hand, a large part of the purpose of CMSs is to allow people to edit the content of a site without having to mess with the code, which might be to our advantage...)
hiddensquire, do you have any idea what the capabilities of the server where you're offering webspace are?
Anyway, that's the backend. For the most part, it will communicate with the frontend only through PHP and possibly Javascript. Creating the frontend will require people with HTML/CSS, Javascript, and possibly CMS template knowledge as well as writers, designers, etc. One thing: I would advise avoiding Flash as much as possible, as security-conscious people often block or uninstall it.
(I'm capable of coding PHP, HTML/CSS and--under duress--Javascript and some limited Flash stuff, but I have way too many projects on the go right now and I'm not sure how much time I would be able to give to this one. I might be of more use as a writer/editor, anyway.)
@Licawolf: The problem options are "Preserve Adobe Illustrator Editing" and "Optimize for Adobe SVG viewer" (IIRC, they're in the save/export dialog somewhere). If you unchecked those, perfect. If not, the file can still be hand-corrected in a text editor (SVG is an XML-based format), so no real worries.