You'll want to upgrade some staves through Trial of the Magians. You'll probably want at least the fully upgraded Thunder damage staff and Ice damage staff.
If you don't have Abyssea yet, buy all 3 Abyssea add-ons. The exp in there is ridiculous, and BLM is very much in demand for both exp as well as gear farming in there.
Lyonheart of Lakshmi
lvl 99 NIN WAR BST THF BLM SCH WHM
1/467 on signed HQ Weskit!!!