@Jim-Daubert hi! it might not be relevant any more (old question), however others might find it relevant.
In Sweden (Europe) there is a company that sells proffesional equipment and non toxic foaming agent called Aercell A-7. See http://www.aercrete.se/20-2/ for more info...
Above product is used by another company that performs construction work and has a data table with ratios of ingrediens and compression strengths. It's in swedish but use google translate...
Also see a video clip!
I'm not associated with those companies... nor know anything about Aercell A-7 foaming agent, but you could contact them... I have a nice home already, but I might be interested in this technology if it can be delivered in a turn key project for nordic climates too, and would than really drill down into agents nature.
Good luck with your project!!