As others have said, lift keys are just marketing gimmicks. You can just crank your stock keys and it will give it plenty of lift. Then you could just buy the rear blocks and new u-bolts. If you have stock bilstein shocks, they should work with the lift blocks, not sure though, someone else will have to chime in on that.
To know how much height you need for the rear, measure the front and rear fenders. If the front is 2 inches higher, get a 2 inch block. If the front is 1 inch higher, 1 inch block, etc. etc.