I recently put Trail Gear 3" lift springs (SUA), Doetsch shocks, and 1" shackles on my Samurai camper. The vehicle weighs 2450lbs on the truck scales as is, causing the back end to sag a couple in inches. I kicked around the idea of "add-a-leaf's", but didn't want the unpredictable ride quality and harshness, so today I mounted some Air Lift air bags without too much hassle. The result is an evened out vehicle with smooth (for a Samurai) suspension that is totally adjustable based on how much weight I'm hauling (food, water, kid, wife, etc).
Before air bags.
After air bags and 2.5" of lift added.
The air bags are rated from 10-100psi. It took 40psi to lift it to where it is now, leaving plenty of range for higher psi for heavier loads.
I bolted and welded the upper mount right below the metal bump stop on the stock Samurai frame. The lower support is bolted around the axle housing.
Not sure if this is practical outside of what I'm using it for, but for this little camper, it works great.