Since Robert DeNiro has already played Vito Corloene, I would think it'd be a no brainer to have him play the role again.

Capone in The Untouchables was a glorified cameo. There'd be a lot more clamoring for De Niro to play Vito than Capone again.

Vito gets my vote.

Let some other schmuck play Capone. De Niro is Vito Corleone.