Hey mooneydiva, this is Bill and as a native South Floridian, AVOID Miami airport all cost!! It sucks!! If I were you, I would fly into Ft. Lauderdale and take "Super Shuttle" down. Ft. Lauderdale is a lot easier to get around, and besides, how's your Spanish?? Heck, I'll even come pick you up to save some bucks for ya. LOL!! West Palm beach is way too far. Not a good option.
Hope this helps, have a great day and let me know if I may assist in any way.