Be glade you didn't buy the Beilstiens, they are much rougher then the Rancho's. You can try to soften the blow by lowering the front and rear tire pressures, a little goes a long way here.
The BFG Velvet Ride rear shackles do work, I've had mine for almost 8 years now, and I even re-used them when I switched over to the Skyjacker rear leafs just this spring. They help take the slap out of the rear suspension when you hit the small bumps. Another great trick is to remove the over load leafs or the stops they hit. This gives a much nicer ride. If you tow, then just remove the over load spring pack and mount up a set of air bags, these do wonders for a much smoother ride.