It depends on the mob you're fighting. If the AE has a -resist mod on it, you'll want to be at 330+. When I prep for trak, I pull 338 PR without a bard.
The sheet here:
http://wiki.project1999.org/index.ph..._Jewelcrafting has all the player craftable items, and the P99 wiki has just about every item and it can be sorted by stats. IE looking for PR gear just look up a slot and sort by PR.
I generally carry around 60+ pieces of resist gear at any given time.
A MR of, say, 220+ at level 60 will hold off most dragon fears.