First I wouldn't feel bad if you can't make it up to him. You could threw him an awsome birthday next year in the USA.
I would just send a card and say we will sell you a belated birthday party within the first month he is in the states or you could write out a love check I owe you a romatinc dinner and movie. They sell love checks on line and then you could put this in the card.
Second if you want to do something in Jamaica for him I would see does he have a trusty friend or family member? I could always trust Dwains cousin once I sent money western Union to his cousin and he bought buckets of KFC and a Fruit Cake. I mailed his cousin the card (global priority) and he got it that day of the card saying enjoy your birthday I couldn't make it but the food, cake, vodka, pepsi, and guniess are me. Have a wonderful night with your friends playing dominos and video games. My husband really enjoyed this one year and he took pics and emailed them to me.
All the best with your decision

!!
One Luv,
Jax