As far as gear goes, do a search of this forum as everything you need to know is in here.
The number one best thing to do to make your chances the best without a doubt is GO OUT WITH A GUIDE the first day of the trip. It is money that could not be spent better. These guys are on the water more than anyone else and when NOBODY is catching fish these guys usually still are. even if you don't get a fish, the information and confidence that comes with that information is invaluable. You could spent hundreds or even thousands for a trip like you're doing so $150 per guy (about) for two at a time for four or five hours isn't much at all really.
The other nugget of advice I will give you is save all the money you might spend on lures where you are and see what is working for that week and get it from Foxies Barra Havoc in Gin Gin. Week to week the may be going for different things and after going out with a guide you will know what those things are. You could spend hundreds on lures and I can almost tell you for sure that they'll be biting on the things you didn't buy (murphy's law). You've got hardbodies they're going off on plastics, you've got plastics, they're going off on bibless slow sinkers, you've got bibless, they're going on giant suspending swimbait smothered in shimano peanut butter.
Josh