If this is for PvE, ditch the rapier. You don't need that backstab bonus for PvE, since any backstab wrecks the enemies that are able to be BS'ed.
Great Scythe - Long Range, Best Damage, slower than the others Iaito - Balanced. Less generic than the Uchigatana, but still abit boring. If you can handle Hp loss, then the chaos blade is amazing too. Gold Tracer - Fast, amazing bleeding. Looks awesome. Shorter range.