Guatemala, actually, is where I was living when I figured out that I had been misdiagnosed and was, in fact, Type 1. It really didn't offer any insurmountable obstacles to me. As I said I could buy insulin otc. I did find an endo in Guatemala City who confirmed my Type 1 diagnosis, but only saw her the once. There is both a small population of ex-pats and a small population of wealthy Guatemalans, so in the city there was good medical care. Everything there was divided into public and private hospitals and the private were up to standards. I don't know that the same would be true in Haiti. But I did have to travel out of the country every 6 months for my visa so could get my needs met in the U.S. on a trip if necessary. Insulin, test strips, etc all available though I did have to switch meter brands.
Downsides: My insurance didn't cover "out of system pharmacies" at the same rate so though meds were much cheaper, my reimbursements were much lower. I never saw any glucose tablets (though I didn't hunt in the city which was an hour away). The pharmacies were always running out of things so I needed to plan enough ahead of time to account for waiting a couple days for a shipment. You didn't have as many choices. For example, Apidra was the only rapid insulin and Lantus the only long acting.
Living in another country, especially a third world country comes with it's own brand of bueracracy which is often more flexible than in the U.S., but less logical, if that makes sense. It can be frustrating, but for the experience, it's worth it. I think everyone should live in another country for awhile. It's an amazing experience!
If you are considering it and this is feasable I would consider a visit first. Then you can check out the pharmacies, doctors, hospitals, etc. Also check in the Thorntree website (a part of Lonely Planet). You can connect to other Americans and Europeans who may be living there and get the "inside scoop". Finally, check with your insurance re reimbursements, etc. One somewhat sneaky option is to get a year's prescriptions before you leave the U.S. Then see if there is a mail/courier service that sends to an address in the U.S. and then courier's it down. I did that for awhile. The courier service isn't cheap but allows you to get mail away scripts covered by your insurance.