Hey Tim I'll b there in Dec. too!!!
My fave beach places for DINNER are:
Cosmos-casual and inexpensive good JA food, local/authentic ambiance
Normas-expensive but good food, kinds inconsistant over the years though (sometimes good, sometimes not so good) ambiance is ok as is the service
Country Country-a little on the expensive side but good gourmet JA cuisine, intimate and right on the beach.
Kuyaba-expensive but worth it, really nice ambiance especially if you reserve the treehouse table.
Margaritaville-good if you want to catch a sports event.
LUNCH:
Treehouse (Allan's Jerk Chicken)
Cheap Thrill Corner-patties and cheap beer.