HTTrack can replicate most of the site, as long as it's html pages and links
(like a traditional site).

What I think William Roeder was saying is that if you want to use the site's
Search feature (if it has one) or it's got pages that rely on Scripts to query
a database to push out HTML, that part may not work.

For what's it's worth, I'd try downloading the site via HTTrack (the price is
right) and then see if the mirror is up to snuff for what you want to do.