I am maintaining the OS X installation instructions for OpenACS as good as I can. If you look at the postgres section, you will see special instructions for Panther, namely, install 7.4 of postgres.
All in all, it is a 20 minute procedure, including download via DSL, if you follow the docs (see my posting somewhere on this site on how to install, as this is a "quick rundown" version of the more extensive documentation).
This said, I did not even try to get AOLserver 3.3 to run on OS X, so no experiences for that one.