Welcome aboard, Jedimace1. PS2Dev.org is the birthplace of the unofficial PS2 development kit, so you might find more specific information there (though I also have admin rights there, so much of the info as of late was added by me). There are two primary graphics libraries for the PS2SDK: gsLib and gsKit, the latter being the most widely used and updated. I don't know of any widely used physics engines or libraries, but I've seen a few adapted for the PS2SDK, for specific use.
Let me know if there's anything I can provide (information, software, etc), and, if you feel so inclined, take a look at Project Artemis
I may be lazy, but I can...zzzZZZzzzZZZzzzZZZ...