Here is another option. It is called a Rack Pack and is a pack frame that doubles as a very nice chair. I have even turned mine around and used the back/head rest as a shooting rest as that actually folds down to as the bottom support of the pack frame. Is the L shape - if that makes sense.

http://www.magnusbroadheads.com/the-rack-pack/

The more comfortable one can sit - the longer one can sit still and sit longer - period.

JW