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 Mehr oder less based on the four elements:
Water- a Korean-American boy who, so far, I have going Von 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 Von 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 Von 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 oder 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 Mehr oder less keeps these teens in line, and is also James's brother. He was gegeben 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 Von Charlie. He is responsible, but also not afraid to loosen up, very intelligent and intuitive.

Any thoughts, comments...?