Pardon me for necromancing this thread, but I think it is important.
I was in need of some PAI models, and had the same issue looking around when it hit me, "why not try the Internet Archive (archive.org)? I've got nothing to lose."
Believe it or not, some snapshots of the site - 2004 and 2006 especially - archived well not just the pages, and graphics, but the actual files - as in, yes, you can download traffic installers, packages, etc. No gaurentee that you can get everything that was on the site, and in fact the paintkits section seem to largely be a miss (for example), but still the fact that a lot of stuff has been saved is amazing.
(Let's just hope another person doesn't buy the projectai.com domain and put a robots.txt file on it - I say this because of the internet archive's idiotic policy of retroactively applying the file to stuff already archive / and purging archived stuff, flying in the face of how it's actually supposed to work [by which I mean how both the robots.txt and internet archive work].)