I would just decide what look you are after and go with that. I have lifted many many 4x4's and my favorite for a full size truck is a 6" lift and 35's if it is a daily driver. Usually a quality suspension lift will have as good and sometimes a better ride then the factory suspension. One thing you will want to keep in mind is your gearing. Do you have the right gearing to handle 35" tires without making it too boggy? regearing can get pretty darn expensive! The 4" lift and 33's will give you a nice look too and will most likely be ok with the factory gearing. I would stay away from any body lift over 2 inches though.