Having spent a little bit of my life wandering around hot and humid garden spots of the world wearing a GI poncho, I just want to remind you of one thing...you will sweat so much under a poncho that you are just about as wet as you would be if you were not wearing it. That said, you can check such places as Campmor.com, they usually have a variety of ponchos, some with a hump in the back to cover a pack and not have the poncho ride up too high in the back...