If Naruto does die he will be represented as a savior of the world and be given a heroes burial with all the cool honorifics that have been added to the series... A huge burial site with a statue and/or an honorific slab with a speech carved into it with a massive funeral and all of the Kages giving speech, His name in the KIA Stone, Statues or memorials in every village in his likeness, a day of remembrance in his honor, given the title of Hokage with his Face into the Hokage cliff.
As for who kills him it will probably a combo of great injury and self sacrifice to return balance to the world and he'll probably not die immediately but have some last words to either Hinata, Sakura, Tsunade, Kakashi or if Sasuke lives definitely Sasuke.