Then I found the Timber Grove ASAM. It installs much like the Total Load Control, but the Ts are brass and seem much higher quality. To top it off, the thing was $383 shipped.
I basically bolted the bags to the bumper cup and the mounting plates on the rear axle. I ran the air line up above the spare tire holder, and installed the valve near the license plate.
So far, so good. You are supposed to keep 10-15 psi all the time, and at 12 psi it lifts the rear end about 1/2". I can post more pics if anyone is interested.