If it is to be Sasuke Sarutobi, he would have needed to collaborate with Tobirama Senju like I stated before. Tobi is in both names so it is easy to see where it is from. Also, I believe Tobi means "jump". How this affects the identity of the character I do not know other than maybe the ability to "jump" time/bodies.
As I stated before, having it be Sasuke Sarutobi would be the ultimate ending to the series, or at least this arc. It would be a complete 360.