Streamers such as these...
...often imitate...
...the local baitfish.

Streamers and poppers often produce nicer fish like this one.

The following is a guideline for the gear you'll need:

Packing List:
Pliers
Hook sharpener
Fishing hat, make sure it has good sun protection
Sturdy rod case (preferably one that you can carry on)
Line nipper
Bug repellant
Flashlight
Sunscreen & chapstick
Stripping glove or sleeve

Clothing:
Fishing shoes
Shoes for camp
Shorts
Swimsuit
Shirts, long sleeve for fishing, short for the lodge
Tropical Travel Clothes
Raincoat
Rainpants
Waterproof bag for the boat
Camera gear(film, batteries, filters etc.)
Sun gloves

Personal items:
Passport
Copy of passport
Toiletries
Reading glasses
Airline tickets
Proof of med-evac insurance

Fly Fishing: Rod:
A 9 weight rod is your best bet for peacocks. While a 10 weight is handy for the fight of a large peacock bass, most anglers will not be interested in fishing such a large rod for the duration of their trip.

Reel: Large Arbor Reel with a good drag

Assorted Fly Gear:
20 and 30 pound tippet spools "
9 foot leaders 20-30lb
Dry line(Tarpon or Bonefish Lines work best in the heat, but you might prefer a weight forward Bass taper)
If you are a weak caster, the Bass taper will be a better choice
300 grain sinking line

Flies:
Bring roughly 4 dozen total flies, one dozen should be topwater flies like the banger, 1 dozen of the big baitfish patterns similar to the Puglisi Mackerel or Keliher Herring, 2 dozen should be of the cheaper variety…while peacocks are not that selective the well tied larger patterns seem to take more than their share of big fish.
Deceivers 2/0, 3/0(on another similar baitfish pattern 4 & 6 inches in length. Colors: Tan/white, Red/white, Red/yellow, Orange/white - Puglisi Tinker Mackerel 3/0 - Keliher Herring 3/0 - Popovic's Banger 4/0 (Silver, Orange, Chartreuse)