Well, Sacha, I have worked behind the scenes at many a folk concert, bringing bands from Europe to the Midwest. To tell you the truth, you and your friends have bitten off much more than you can chew. Sending new performers from Europe to the Caribbean is too much.

If I wanted to organize tours, I would start by taking a job in the office of an experienced talent agent and learning the business. (It would probably help if I didn't have a whole lot of scruples.)

For example, someone writing above mentioned a performer who had to do a lot of backtracking by air. That was because his agent had made a deal with a certain airline for the cheapest of fares, and getting the cheap fares requires travelling from that airline's hub. That's just one of the many wrinkles of the entertainment business.

Failing that, you should start out by organizing tours right in your own country. Then move to gigs that will involve short air hops nearby. (Why not use a travel agent?) Only when you have a lot of experience should you do something like moving a band from Europe to the Caribbean.