I really think that sasuke wants to talk to 1st and 2nd hokage to understand why the uchiha wanted to attack or some past uchiha. Then again maybe the elder son and younger. Or the sages any of them but other then them I cnt think of who they are.
I doubt it is going to the son or the sage because sasuke wants to know about villages Bak then ninja villages didn't exist so you would think that it has to be the first hokages or madara or someone else from that time, because if you asked the sons what that was they would look T you like if you were stupid.
Ugh, it's so obvious, what he wants to talk to them about. He wants to know, why the Uchiha clan agreed to found Konoha with the Senju clan. Then he wants to know, if the Uchiha was made the police corps, to put them on a side track.