ALL a leveling kit is IS new keys for the front, and coil spring spacers in the back! That's it!
Some "kits" add shock extenders for the rear, and most don't even bother with the front shocks.
You can easily get some Z71 coils from rockauto.com for about $50, get your own coil spacers (got mine off E-bay, about $28), and keys (again, E-bay, $32), along with rear shock extenders (E-bay, $19). Also bought the correct Torsion bar tool (E-bay, $30).
I also ordered new shocks while I was at it, I went with KYB's, a little over $100 for all four. Bilstein 5100's will set you back about $300.