Rapier if you are pking Vs. anyone with a high defensive armor, or if you are just doing general slaying.
Maul if you're a pure pking, or do bossing a lot
Longsword if you do pretty much all of the above.
I apologize if someone else has already brought this up, but there is a way to use mouse-keys to clean a full inventory in a matter of a few seconds. I would try looking up a guide on YouTube.