So, Barret has a Chainsaw for a weapon, what about the Lancer from Gears of War (the machine gun with a chainsaw attached).
Household items wouild be kind of funny, especially on Cait Sith. Seeing him a frying pan or spatula would be kinda funny. Cid with broom, too.
It might be funny to give Cloud a dagger. He'd still use both hands, but the blade would be really small.
I love the lightsaber, what about Darth Maul's double lightsaber for Aeris (would be sweet) or Cid.
You could give Yuffie a Spartan Shield, a la the 300. Also, seeing King Leonidas in the game would be awesome.
More axes would be cool. Keep up the great work!