I think it will be the second possibility. depending on whether sasuke comes back it will be either a naruto and sasuke vs. madara or a naruto vs. sasuke and madara is going to be killed in the next few months.He will probably become Hokage and then meet Sasuke or become Hokage right after his fight with him. Then Madara`s next or something..
In any case naruto wont be hokage until sasuke switched sides again, naruto repeats that permanently through the whole series.
btw: i dont think that we will see another 200 mangas, i think it's gonna end in the next six to twelve months. most of the evil guys are down and the main characters both count to the strongest chars in the series.