Let analysis what Sasuke and Neji have:

Sharingan vs Byakugan:
Rock Lee had said, close combat user is natural enemy of Sharingan. Even Sasuke may able to see Neji move, unless Sasuke can catch up Neji speed, Sasuke still has trouble with that.
One the other hand, Byakugan gives Neji 360 degee vision + Kaiten, which leave no blind point for sasuke to attack.
By the way, all technique Neji know are blood-line technique, which sharingan cannot copy.

Chidori vs Kaiten:
Both Chidori and Kaiten are chikra, so base on which one stronger. Let say Kaiten cannnot block Chidori. I believe Chidori is linear attack (and kind of slow as well), and required hand seal (which mean cannot link from previous attack). Even without kaiten, there is no way Neji will hit by it. Neji could dodges Chidori easier because he has 360 degee vision + speed. The only way Chidori may hit Neji is when Neji cannot move.

Divine 64 Strikes:
Actually, 64 or 128 or even 1024 strickes is not the matter. The main thing is can it get it or not. As long as Sasuke keep long distant, this attack wont' work. But once Neji hit, sasuke lose.

Blood Seal:
It is double edge sword. Yes, it increase the chikra, but also use up much faster. If Neji use "hit and run" and "time consume", let sasuke use up most of Chikra, Neji win.

In order to make Sasuke win:
Long range attack Neji, or shoot chidori to Neji blind point from 300 Meters away, or find a way to slow Neji movement, then chidori.

For Neji to win:
Just keep in close combat in 360 degree range. Sooner or later, sasuke will use up chikra then Neji can win easily. Or wait for the chance to use Divine 64 Strikes, since Sasuke defence is not "absolute defence", which mean full of flaw...