It's hard to advise you based solely on the information you have given. Nonetheless, I can guarantee you that getting a law degree in US of A will be a HELLUVA lot more expensive than doing the same in UK.
Further, I'm not clear on your eventual goals- you want to practice in US? For Life? Become a citizen? I mean, if you sorta like the idea but really don't want to give up your life in Britain, then I recommend getting a degree there and get employment in
International Law with a firm that does a lot of business in the USA, preferably work that requires you to visit for months at a time. It sounds like you have the kind of connections that would be possible for that. But if you want to STAY in the USA then come here. How you would finance it would be another story. Still, there are scholarships available if you became a citizen especially.