Thanks for all of the great feedback. I'll check out all of the cards mentioned and ensure that I look up what it would take for a few specific trips and go from there. Also a really good point about loading up all of our US purchases on a US card just before traveling to hit the spend limits.

Man, do I wish student loans were payable through credit cards, I'd have tons of miles/points in no time! But for now, just putting regular expenses on the cards with 0% foreign transaction fees should be a good way to go.

Thanks again for all of your help!