Weapon of choice for future DPS?

[Shurrikhan]

I realize it's primarily a caster, but RDM wields a Rapier. And Samurai wields a Katana (a type of sword)

The logical (impossible) choice: Fencer should have been a base class for Red Mage and a viable end-game alternative acting as a second, branched job... Continues to use a main gauche rather than swapping the offhand to an ACM (aetherocrystal medium, or w/e it was called).