www.boulderbars.com pretty much has all the info you need right there. There's been atleast 5 or 6 threads that contain all the info you need in the past week or so...I know the search sucks but it's a pretty frequently asked question. All you gotta do is look back about a week....
There's basically 2 types of gasser lifts....the Frankenlift which comes with rancho struts and shocks....and the Premium Frankenlift II that comes with upgradable OME (old man emu) HD struts and LT (long travel) rear shocks. This is the better package and is better if you plan to add aftermarket bumpers or other parts. It's your best bet in the long run IMO.