I find it surprising to note that most english teaching jobs in china come up with a prequisite requirement of "native english speakers only". Do they really think that people who are not native english speakers do not have a good grasp over the language? Or do they really think that just because a person is native english speaker, he is automatically qualified to teach them the language? Perhaps, they would find it surprisingly shocking to note that many uneducated "native english speakers" can't write even their own names in their native language !!
Broaden you horizons and look for people who have some good qualifications rather than just look for "native english speakers" .