There is quite a price different on either options.
Mind you, readylift is a premium level kit. But it's a good level kit.
We have sold quite a few of readylift levels and those that went that route, went with a 1.25" body lift to get 3.75"-4" of lift.
CST is a great kit. But it's the same dilemma 4wd guys face.
Do you go suspension lift or level and body lift to achieve the same thing.
Neither is wrong. It just depends on what you want to spend or can spend.
Let me know if you need any pricing