Talon,
I agree with Mr. Green on all his points, and will just tack on a bit from my experience last year.
I have interests similar to your own. Ultimately I decided to go for a public policy degree and focus on international finance. This way I will be able to take IR and finance classes to help with marketability in the private sector after graduation. It sounds like you already have pretty outstanding experience, so that should put you a step ahead of many grad students as well.
I'm sure you're already well aware, but I'd look at SAIS, Fletcher, SIPA, Walsh, GW, American, HKS, Goldman, Maxwell, UMich, UTAustin