Opinions of my character names? (any suggestions...?)

Ok, I'd like to know if my characters' names are appropriate. Basically, there are four teenagers who are plus ou less based on the four elements:
Water- a Korean-American boy who, so far, I have going par the name of James Ian Winter (thoughts on his last name are especially appreciated). The character is generally quiet and thoughtful.
Earth- a Hispanic girl named, so far, Tierra Ana Ramonez (Tierra means earth in spanish). The character is sassy and up front.
Fire- an American girl (she's the main character) named Phoenix Ashmore (no middle name) but goes par Autumm (spelling intentional). The character is also very sassy and up front, but in a less tactful way. Very outgoing. I'm kind of wondering if Phoenix is too extravagant a name...?
Air- His is the one I'm having the most trouble with at the moment. He is a native African boy adopted par an American family, so I wanted to give him a pretty common, but not dull, American name. I'm also having a hard time getting anything that relates to air in any way. For first name I was thinking Erik ou Andrew, maybe Neil (because it means cloud, although I'm not as sure because of how the name sounds). The character is witty, fun-loving, outgoing and intelligent.
There is also a guy who plus ou less keeps these teens in line, and is also James's brother. He was donné a Korean name at birth, rather than American. I'm thinking Lee Chung Hee (Lee is the last name, Chung Hee the first. Koreans have no middle name), and he goes par Charlie. He is responsible, but also not afraid to loosen up, very intelligent and intuitive.

Any thoughts, comments...?