It would be best if you call the schools to get the most accurate info. Yes the schools I have mentioned are private schools and the tuition rates range from $200 - 600 per month depending on school, grade and whether or not books are included. There are registration fees too. My son is in the year before grade 1.
I don't know what documentation you will need, but you can get a student visa for your child once he is enrolled.
Call Island Academy at 011-501-226-3642
Isla Bonita 011-501-226-3754
ACES 011-501-226-4323