you know, before you all you fanboys decide this is a curbstomp battle, who do you think would win? Itachi and he are both at full power, and are on that lake that Naruto and Sasuke fought on, so Kisame is pretty much at home I guess.
You really have to remember that it even stated that the Akatsuki were using 30% Kisame's chakra to take Shukaku out of Gaara (while the other 9 members gave in, too), meaning that Kisame has a metric @$$load of chakra. Bet none of y'all remembered that :P
I honestly don't know who would win this