Be careful with timbrens/sumo springs guys, on the other forum there are reports of cracked frame right above the timbren, the theory being the frame is hitting with far more jaring force in that area as compared to stock springs which are softer and absorb the blow.
I changed my mind on all these helper things a while ago, if you need them that badly while also using a properly setup trailer and WDH, then the truck probably just isn't big enough and its time to upgrade. I just use a good WDH and that took care of my sag/bounce issue. All IMHO.