If the "jungle" is soft and/or light and springy vegetation, you want a very thin and light machete. Try something in 1/16" stock, Ross Aki makes one that has recieved positive comments.
For heavier wooded areas you want a thicker blade to allow a more powerful stroke, Barteaux makes a model with a number of strong features, there is however the downside of a very poor NIB edge.
Barteaux also makes lighter models, I have not used them though.
There are a number of custom makers who will make machetes. If you can be very specific about what you want, and you pick the right maker you should end up with an optimal blade.
-Cliff