Being a moderator on a couple of V-Bulletin sites, I have no qualms about using that particular forum software.
We still have problems with spammers but nothing a bit of light moderation can't handle.
Persistent trolls are another problem though and IP banning is not an option due to the shared nature of dynamic IP pools. Banning on range usually ends up us banning thousands of innocent customers of the ISP which owns that range. Filtering known proxies helps weed out attempts at re-registration though.
Basically as you already know there is no watertight spam proof solution.
You can tweak the theme to give the site a unique character to differentiate it from all the other VB sites out there but you still lose the flexibility advantages of a CMS.
Maybe something can be hacked into it to give you the required features.
Your decision though. I appreciate that it is not an easy one to make. I'm sure well get used to whatever route you take for the upgrade.
P.S
If the Auction Ads are not really bringing in any revenue, I would scrap them. They really slow down the loading of this site.
