I would look around for the stuff you need you can find better prices then this try pepboys or autozone for the rear blocks they will be cheaper than ordering them from internet
if you go with the 3" sprngs and 4" blocks.. all you will have to do is buy new shocks... no cutting. if you get the spindles, you wont need new shocks, but you should anyway.
1/2 turn on the coil = 1" drop. so 1 1/2 turns cut off, but you would be better off to only cut 1 full coil off first, reassemble the suspension, and see how she sits, you dont want to cut to much teh first time... you can allways cut a little more off later.