J1 internship eligibility query

[bored565]

I'm a British citizen on a gap year, having finished Sixth Form in June 2014, and would like to apply for an internship in the office of a US Congressman. I've checked with several offices and the central employment office, and they've said they have no issues with hiring a non-US citizen, but I'm finding the biggest stumbling block to be getting a visa - which one would be applicable for someone in my position? J1 internships are apparently only for those in university, so I'm basically stumped.

Comments and advice would be much appreciated.