I'd say it would be possible, but you would have to sign all legal rights over to the person your son would be living with, essentially he'd have to be adopted and I don't believe that would happen in time.
However, if your son would like to go for 6 months to 1 year, you could look into high school exchange programs for the year. When I was in high school, we has several Germans and Italians there on an exchange program.
Not sure how great this site is, and might be able to find more info on the web, but you can have a look at this:
http://www.ayusa.org/study_us/study_us_main