We kept the insurance we had in the states before. Due to obamacare our previous plan was shut down (as it became illegal to sell lower cost plans like it) and we were put onto a more expensive plan. We're researching our options. But we may end up buying insurance in the USA and then supplementing it with World Nomads coverage. They charge around $50 a month and provide $500k emergency transport back to the US (where your insurance will cover you) plus a variety of other benefits. WorldNomads.com
Some of the other companies we've heard about are mentioned in this article, but we don't have experience with them:
http://www.nomadtopia.com/faq-what-do-you-do-for-health-insu...
Sorry, I can't give a definitive answer on the solution, but this is an area where we're still learning.