I would be scared to air them down as the tread can separate from the carcass when doing it, plus sidewall strength would be extremely marginal on these unless you get the matching carcass of say an MTR or similar.
It even says in the FAQ section on that site that airing them down voids any warranty at all.
FWIW, I just bought a set of Hankook Dynapro A/Ts for $99/ea. I have read great reviews on them in the snow/ice. Mine went on a new to me 93' 4runner. I have also had great results with the Yokohama Geolander AT/S as well, but liked the extra siping on the Hankook for a DD in Colorado.
Here are the Hankooks
Onlinetires.com - Lowest Tire Prices on the Web. Period!
Discount Tire matched the price in store. But after tax. mount, balance, etc it was $540 out the door for all four with the warranty and lifetime balance/rotation.