A few other CPAN modules might be useful:
WWW::Mechanize and
WWW:WebRobot. I've only used these for automated tests. I guess in your case, you still need to change the link in the original page (say images) to local copies. w3mir can be used for downloading a whole subtree, most likely can't do exactly what you want since your page can (theoretically) include an image from somewhere else.