Luke,
Welcome to the GT fishing addiction....
Andrews' words are spot on.
You must learn a good knot and be able to tie it competently, there isn't a worse feeling than losing a good fish due to knot failure.
Black Magic makes good readily available leader. I use 200LB supple and crimp a swivel to the business end, other guys tie Uni knots. Whatever you decide to use, do it well...
Also find out how many people on your trip are interested in this style of fishing. There is no need taking 20 GT lures if no-one else is interested.
As for poppers and stickbaits, you can spend a small furtune if you want. I would start with some of the better, less expensive, offerings available from our forum sponsors, but purchase the expensive ones if you wish to. Be careful...its a drug....
Heru Cubera, Ulua, Wahoo and Bobara, Jai Bighead, and Adhek Venus, PeniPen and Goby are all good lures that won't break the bank. Also read Brandons very good Recomendation for Poppers. It contains a lot of excellent info.
Make sure you purchase quality terminal tackle as most GT lures come without hooks and splitrings. Owner, Decoy and Shout are all good brands.
A good gimball belt, waterproof tackle bag, casting gloves and sun protection are all must haves.
Above all, perservere, learn and have fun!!
Ken