Part 1 Kabuto? Wasn't he said to be nearly as good as Kakashi and better something than Tsunade. I think he also took out a bunch of anbu and put a whole stadium to sleep although they were probably fodder. Kabuto wins.
I wouldn't say Kabuto was equal to Kakashi. While he may be highly intelligent and that can be equal to Kakashi but in overall abilities, from what was shown, Kabuto gets beat by Kakashi 8/10, sorry.
But on to this. Naruto "defeating" Kabuto was bs. Kabuto had a good arm and just stood there, didn't attempt to move, just let himself get hit while Naruto had the time to create a shadow clone and form the Rasengan. That was just plot.
For Sasuke, he stomps Kabuto. With the speed he picked up from Lee and the Sharingan at his side, it's over for Kabuto. Sad to say. Kabuto is good but he was never the battling type.
Honestly I don't see what's the big deal about Kakashi. He's admitted he has low chakra, he claims to know 1000 jutsu but has used like less than 20, making anbu isn't that much of a feat even if it is above Jonin since Kabuto took out multiple and look at when Anbu is shown and look at the fillers who don't have tremendous skill but still are in Anbu, Kamui takes too long for him to charge and is too straining for him. His taijutsu is good tho and you know RAIKIRI!!! But comparing him to the Naruto verse I would at least think of him in the Sannin realm but he wouldn't be able to beat any of them. His strategical thinking is good that's what could make him kage level shinobi but every Kage is smart and other than that he's nowhere near the power of like 90% of any kage that were ever shown.
I don't agree that Part I Sasuke would win, but I do agree that Kabuto would have an extremely hard time beating Sasuke because at that point in time he was a little more skilled in Naruto in battle but after the 3 Sanin arc Naruto became a little stronger.