Watch Deadliest Warrior
! It's on Netflix and Spike TV if you have cable in the U.S. The last season has been ridiculous with vampire v.s. zombie type battles, but the first two seasons have matchings like vikings v.s. samurais, apaches v.s. gladiators, Persian immortals v.s. Ancient Celts, IRA v.s. the Taliban, etc. and they show off weapons that they use/d. The show is pretty silly but I've learned a lot about weapons and armor.
I like the idea of each weapon having benefits and drawbacks. Would all of your characters be able to equip any weapon or is each one limited to a few? That'll be important in setting up battle strategies.