The way the torsion bars work is that they are essentially bars loaded in torsion (twisting load). The bar's resistance to be twisted creates a reactive load and provides enough force to suspend the truck's weight, just like a spring. When you tighten the adjustment bolts, you are twisting the bar more, which creates a larger reactive force, which lifts the truck. Hence our term torsion twist.
The Warrior shackles used in the Shackle Lift are simply replacement leaf spring shackles. The leaf srping shackle holds the end of the leaf spring near the rear of the truck to the frame. The Warrior shackles are longed than the stock ones, which pushes the spring down farther away from the frame, and thus providing lift.
If all you are looking for is about 2 inches, then cranking the torsion bars up a bit for the front and adding the Warrior Products (WAR-153) shackles to the rear will yield about a 1.5" - 2" lift. The torsion twist is free (do yourself) and the shackles will run you about $50. Plus you'll need $$$ for a front end alignment, but overall, pretty cheap and easy way to lift. MANY people on this board are running this way and there is even a tech article here:
http://www.explorer4x4.com/torsionbars.html
You might want to try a search for Torsion Twist, or Torsion Bars, or Warrior and you'll find plenty of good information.