Randall's Adventure Training (RAT) is run by people with very extensive jungle experience. Check out their info.

One jungle trick that the SAS uses (verified by a pal who is retired SF) is to keep 2 sets of clothes: one for hiking in the day and one for sleeping in at night. The day set gets (and stays) wet, while you keep the night set in a waterproof bag during the day. It sucks to put on the wet clothes in the morning but it is great to sleep in the dry set at night.