So whats wrong with the coil buckets?
The radius arms would keep the axle from wraping and any forward-backward movement. The Drivers side drop bracket can just be removed, the passenger bracket is already controlling the left-right on the passenger axle. The only issue I see is that the Trac bar would bind, so heims would be in order, and a limiting strap.
I see what your saying for a 4WD model though, would it work for just the tube on a stock suspension 2WD truck?