Brion-
I haven't used it myself, but it sounds like TWiki will be better suited to what you're trying to do than trying to hack a different workflow onto Wikipedia.
See: http://twiki.org/
I advise against it. TWiki uses CamelCase, which makes it impossible to store data in a normal form -- EverythingStartsLookingLikeThis soon enough. It also requires registration before editing and has a terrible user interface (with lots of curly braces and inexplicable link names). Very geeky, lots of features, but quite user-hostile.
If you want a simple wiki, stick with UseMod. It has all the features you need, there are lots of cool hacks, it's super-easy to set up, uses almost the same syntax as Wikipedia (which formerly used UseMod) etc. UseMod is still an extremely cool general purpose wiki. To see what you can accomplish based on it, take a look at UnrealWiki, which uses a beefed up parser and lots of CSS (the parser is open source):
http://wiki.beyondunreal.com/wiki http://wiki.beyondunreal.com/wiki/Wookee
Regards,
Erik