The benefit of sending kids to U.S. boarding school is to teach self-independence and to explore and improve the child's potentials, especially with academics, sports and extra-curricular activities as those are really lacking in China. I understand your son's English is not up to standard yet but kids at that age will learn very quickly given the opportunity. If your goal is to have your child attend U.S. schools, I would suggest that during this year, you find English programs that can allow your son accelerate in English. Until such time his English is at a level to allow him to read, write and communicate well, there is no sense sending him abroad because he will have a miserable time. You need to prepare him well if you want him to succeed.