I don't really know who to give the victory to but since you are a Neji fan and decided to give him the victory with difficulty, it shows you aren't biased unlike some other fans on this site. I find it quite silly that some people say Kankuro loses to Neji low difficulty. If I were mean I would neg rep for the stupidity but I won't.
In part 1 I'd give the victory to Neji high difficulty but in part 2, Kankuro is a beast and Neji hasn't yet to show something totally spectacular that sets him apart from part 1. For this reason, I give the victory to Kankuro mid-high difficulty.
According to the data book, Kankuro has more stamina than Neji and this makes sense since Kankuro uses puppets which aren't very chakra taxing unlike Neji whose move set is a lot more chakra taxing. To put things simply, Neji will eventually have to stop rotating to conserve chakra. Also bare in mind that while Neji is rotating, he is a stationary target and can be poisoned by gas easily since his defense won't prevent air from coming in or else he would lack oxygen.
Also if Neji cuts Kankuro's puppet strings, he can simply reattach them, so no big deal there. Kankuro's puppets are too durable to be destroyed by gentlefist especially his Sasori puppet and Chiyo's mother and father puppet. Also Neji can't simply destroy the chakra points in Kankuro's puppets since they have none. Lastly Kankuro's intelligence is on par with Sasuke's while Neji's is on par with Naruto.
Neji is strong but with lack of feats and a bad matchup, he can not win this fight. Kankuro mid-high difficulty.