Ok lets see here... I go with neji mid difficulty and heres why
1) 8 gates is countered by rotation, yes rotation not only blocks but reflects physical and chakra skills. also it requires not a lot of chakra. 8 gates runs out very fast.
2)lee HAS to close the distance, on the outside neji pepper him with air palms and is very accurate, he could amp up concentration and really finish him.
3) IF Lee does close the distance, he will get obliterated, his taijutsu is just as good physically but people forget just a touch from a hyuuga triggers immense pain and could be fatal. also within the range of neji's 8 trigrams lee will not be able to get away from 128 palms, ALSO dnt say speed because neji has faster hand speed and thats all that matters since lee HAS to close the distance
4) Theres a reason why lee admires neji and calls him the best gennin out of the leaf (excluding naruto and sasuke he was), theres also a reason why neji is a jounin and lee is not.
5) In summarym he could not beat him in part one and part 2 shows no evidence of him improving enough to beat neji, in fact it would be the opposite seeing how neji has made it jounin and lee is a chuunin, also in reality 1 hit form a hyuga means death if done in the right spot.