I'm aware of the main OSTs, but I don't know anything about the songs from the expansions.

In particular anything post-Chains of Promathia, including the Abyssea and Shantotto expansions.

Thanks for any info and rips.

You'd be looking for Final Fantasy XI Original Soundtrack -Plus- for the 3 scenario (Crystal, Moogle, Shantotto) and Abyssea. You probably already know ToAU and WotG have their own soundtracks.

SQEX-10284~5 | FINAL FANTASY XI Original Soundtrack -PLUS- - VGMdb (http://vgmdb.net/album/28520)

There's probably a link somewhere for it since FF soundtracks are popular.