Are you replacing the whole lift, or just the shocks? Rancho RS9000 is a line of adjustable shock absorbers, not a lift.
In the event you are asking about a lift, I would go Skyjacker of the 2 you offered, and I would consider BDS and Tuff Country if I were you. Of the 4, BDS and Tuff Country will be the best riding, best flexing lifts, followed by Skyjacker then Rancho. Tuff Country will more than likely be the cheapest. I would choose a BDS or TC lift, and use the Rancho RS9000X shocks.