Looks awesome E-nat, I like it. I really like how you made their hair, and Gaara's sand looks cool to. I also like the appearance of both characters clothing, including Gaara's sand container. The folds, and wrinkles in Lee's clothing look very accurate in consideration of his movement. Overall, the characters look really good, especially Lee.
Alright, now for a little criticism about Gaara, hope you don't mind. The first thing I noticed when looking at Gaara, was that it looks like he's dancing. It's the position he's in, and the way his arms are held are out with his fists closed. It almost reminds me of a dance style from the 1990's, but I forget what its called. Well, the only other criticism I have for you, is about Gaara facial expression. Gaara seems to be smiling at Lee, so the mood of the situation doesn't seem right to me. Gaara started his fight with Lee calm, but had bad intentions throughout the whole thing. After Lee's speed became a factor, Gaara eventually became very frustrated, and angry, which is why I think I a darker, more angry facial expression would of been more appropriate.