Greetings HazySolidFlame and welcome to Ultima!
For finding any non-event rares, consult the drop table here:
Ultima Drop Tables
For server exclusive and event drops, look here:
When Can I Hunt _________? Guide to Ultima Server Events
As far as meseta goes, occasionally the GMs will setup a meseta room full of stacks of 999,999 meseta!
Therefore, keep a sharp eye open when you see it on the room list in the lobby and try to get in.
Hope this helps and enjoy your stay here!