I just want Naruto to get some kind of unique weapon.
like one of these toad swords
But since His main element is wind and his second will most likely be water I propose that he get a hollow weapon, like a staff. He could store water in it and use it in his jutsus untill he gets to ni-daime's lvl. But if he must have a sword I suggest something like soul calibur. It could work like a tuning fork so he could learn the sages genjutsu. Since it attacks the senses instead of the chakra network It could probably work on sasuke