should i use sword in main hand, and dagger in offhand?

should i use sword in main hand, and dagger in offhand, or both daggers? i read some threads in here, and i think i wanna level in the combat tree. i see in AH that exists an one handed sword (Defias Rapier), with 1.6 speed. wouldn't that make it a dagger, since it has such a quick auto attack?