Itachi wins. Med-High
Whiterage doesn't work on Itachi since he's edo and doesn't have bones. So he puts up a Susanoo like he did in cannon. The only real threat Kabuto possess here is sound genjutsu and since Itachi and Sasuke both proved that they can use their Dojutsu abilities while under the sound genjutsu not even that will work against Itachi.
Manda 2 gets sealed via Totsuka it's way to big to dodge so that's not an option. Kabuto also can't do anything to a v4 Susanoo.