If its all the same to you, then I would go with the lightest system. Payload gets eaten up very quickly, 50 lbs here and 50 lbs there chew up available payload. I run with Air-Lift 5000 with internal jounce. The internal jounce is recommended when you have to remove the OEM jounce pads to install the airbags. 7 to 12 psi gives a noticeable improvement in unloaded ride, and 50 psi gives a good leveling of my load, 55 lbs gives me a nice rake when loaded. But I don't know what your tow vehicle is, if you are trying to support an overloaded truck then you need to address the springs, if your looking to level your load then the bags are your answer.