Try Mountain Air Cargo. They are a FedEx feeder based in the Southeast. They fly to Central America and have pretty good pay/benefits. Also, since the planes are owned by FedEx, they are pretty well equipped, and the maintenance is top-notch. The only drawback is that they put you where they need you based on staffing needs. Once you get some seniority though, I'm sure you could get a route going to Central America.