Wonderful Weaponary

Weapon options seem to be, from BBB:

Orca-Hunter's Harpoon from Heroic HoR first boss
Marrowstrike from Heroic ToC but only if you get Paletress
Tower of the Mouldering Corpse from Normal FoS end boss

Or Staff of Feral Furies which is grindable and I have already. Thus the only upgrades are drops from instances, one of which is even a normal one, so can be ground but not using the dungeon finder I'd warrant. The best is from Heroic HoR which can be horrendous with the wrong group, so the one from Heroic ToC looks like a good bet - queue for Heroic ToC explicitly, hope for Paletress. If failure, queue for normal FoS and hope. Only a madman queues for Heroic HoR by choice.