Re: Leveling rear to front ??
With the CSC kit, you're likely to sit low in back, especially if you use 5-pack springs up front and 4-pack springs in back. I used 5-packs at all 4 corners, which helps level it out, but any significant weight in back brings the rear down again despite my long rear shackles. But my Samurai is a hardtop, with a heavy rear bumper, tire carrier, gas can, hi-lift, and oftentimes passengers in back.
But it sounds like you have the Calmini or Warrior shackle reversal kit, in which case some longer shackles in back would probably help out. You could go with some slightly taller springs in back too. I wouldn't recommend a set of Add-A-Leafs though, because they'll make your ride terrible and severely limit your articulation.
-- Geoff Beasley