Brandysull tends to go in-depth with the phone tech. Basically - if you're going to do calling a lot go with DIGICEL. If you're looking for data then go with LIME/FLOW.
You said data so here's my take. If you're going to be in the towns mostly and main roads then LIME/FLOW. If you going be off-road or in bush - DIGICEL. The best thing to do is to ask someone that has the service in that area. Can't give you much feedback otherwise.
Knowing the solution doesn't mean knowing the method. Yet answering correctly and regurgitation are considered "learning" and "knowledge".