Fixed up version of Isla Paradiso, all ready to play as a saved game: http://forums.thesims.com/en_US/discussion/811253/removing-ip-lag/p1
You don't have to follow @ciane's pages of instructions if you don't want to, those are for the Do It Yourself crowd. :)
For custom worlds, perhaps something here will be of interest: http://nraas.wikispaces.com/Worlds%20Recommended%20By%20Wiki%20Members
Enekjaer Island from that list is very popular, although not exactly what I would call tropical. I don't think it comes with a resort, but those aren't very difficult to add by comparison.
