For highest DPS, dual wielding might be better, since you will be able to equip two weapons that each give different status ailments.
IE: my current rogue has two daggers each 50-100 peircing damage, and one has a 20% chance of inflicting burning, and the other has 15% chance of poisoning. If he hits hard, it's ~200 direct, and both burning and poisoning the target.
I have seen two-handed weapons that do over 200 damage _and_ inflict an ailment, but for max possible DPS I think double ailments might win, especially if the character is strong _and_ lucky _and_ has a leader nearby (chance to hit (and apply status) goes up quickly with good leadership nearby.
