Gas system for world cruising

[AliaVita]

I hope someone with experience can give us a little guidance here. We have been living on board our French yacht in the Med for 4 months now, and have almost exhausted the gas supply from our two 13kg bottles. We can't get them re-filled in Spain but do have enough to get us back to France in the next week or so. In November we head for the Caribbean with the ARC and plan to sail extensively in the US, Caribbean and Pacific over the next few years.

I assume that the french bottles can be re-filled in French Carib islands and French Polynesia, but this is an assumption. I have already assumed a few things about how the French do things that have been proven not to be correct!

The big bottles are great and we don't really want to go back to the little 3kg Calor bottles. Do I need a selection of systems or can I get by with what we have? Any guidance from experience much appreciated.