Funding really is hard I am afraid. Services for Belizeans such as you describe would be wonderful but unless another cash stream can be developed you would pay a lot for the privilege of providing them on AC. The idea with South Beach was there would be a minimum of 5000 North Americans in residence at any given time and probably 4 times that in the winter. Medical Services would have to be provided, particularly since retirees might start to predominate. Some sort of facility would be required and that would of course be available to everyone. No support would have been required from the GOB or charity.
Hilton actually does this for retirement communities in Mexico.
Of course, there is growing opposition to South Beach for many good reasons so this avenue is probably out.
Talk to Dr. Gonzalez the next time you are there about average payments, supply problems, enormous duty on medical supplies etc. I don't mean to discourage you at all but it is very different from the US.