Maybe the walls could be formed using Gabion and then coat the outside with a structural parging like they use for stacked concrete block structures. This should stabilize the walls while cutting down on air infiltration.
I too have been looking into this for a possible weekender home out in East Texas. Also, been looking into the following:
http://masongreenstar.com/ These folks supposedly have a papercrete style product that could be used for building.
Just my 2 cents ....
