You will shave some weight off by using lipos. I think 4 or 5S lipos will be a nice up grade for your truck. It will also take out some of the load causing you to have that weak link in your set up.
i would love to lighten my rig,BUT...i have 12 matched packs,NOVAK equalizer/smart tray,2 millinnium pro chargers and NOVAK power pack that i am not ready to scrap!...YET!