I thought about that but honestly I'm not very mechanical and would like to have it all done with the same kit and all at once.Your question was answered in your question
Look into the zone 5" and bds shim for a total of 7" lift. Costs about the same as the rc, and an inch higher.
Sorry if I went on and on in my original post and was a little confusing. I would like to hear from the Rc lift crowd if they are happy with their lift or wish they would of spent the extra money and went with the bds or a diff kit.