I can understand your hesitation to want to host the site in the “cloud”, but I believe Pam has already had a couple of offers to host the site, so finding a safe hosting option should be easy enough. (As long a the organizations offering to host it don’t go bankrupt or lose their funding.)
If you think that MediaWiki is ugly, fair enough that is a personal call, but I disagree with you about it being hard to navigate. How easy it is to navigate is totally dependent on how it is set up. If a bit of thought is put into setting up the site that shouldn’t be a problem at all.
Do you know of a good public DokuWiki site? I’d love to have a look a one to compare it to MediaWiki & WikiDot.