Gaara would win. He's a kage level fighter who has showcased feats that outshine nejis completely
I doubt Neji could fight with Gaara and his sand effectively. Sand Coffin and be done.
even so, Gaara stil has feats that far outstrip neji's. He can only rotate for so long before he gets exausted(Neji should have less chakra than Garra) and Gaara crushes him
@5th: Gaara can fight effectively in a distance so Neji has no chance of hitting him with the gentle fist. And even air palm isn't powerful enough to break down his defenses. Basically Neji has no chance to win.
Gaara. He is Kage level. And his ability for long distance is the perfect counter to Neji's fighting style. Plus, depending on where the fight is, he will have complete control over his surroundings.
Neji, for the most part, is a melee fighter. While he has techniques in his arsenal that can fend off ranged attacks, he doesn't necessarily have many effective ones for ranged combat. Gaara's combat style is mostly focused around ranged combat, Neji's worst kind of matchup. That, combined with the large amount of area that Gaara's sand attacks can cover in their stronger variants, will screw Neji over in the match.