People are going to say get as low as possible MF and kill cows. Another option might be armour racks (LK, countess, Meph, etc? There’s all sorts of theories on armour racks I’m not familiar with so do your research.
Ultimately you want a 40+ res Eth sacred targe as it offers the best block %. I think Vortex is over rated tbh.
I found an eth Kurast with res off of nihlathaks minions during key hunting.