See Um Lodge will furnish all of your flies. You may also bring some favorites from home. Either neoprene or gortex work well. You will need felt soled wading shoes but absolutely no metal cleats or spikes as they damage the aircraft and boats. Typical fishing clothing consists of poly underwear, pile jacket, hooded sweatshirt, and a good fishing rain jacket.
Fingerless gloves are nice for cold mornings.
Dress at the lodge is always informal. Needle nose pliers for releasing fish. A good pair of nippers. A camera and lots of film. Insect repellent and a head net if you are extremely sensitive to bugs.