Add a Leaf Options and Advice (Gen 1)

I'm looking into add a leaf options for my 2003 Tundra to beef up the rear suspensions and prevent sag. I'm thinking i'll throw on some 5100s and then Add a leaf to the stock Leaf Springs. Is much difference in the quality of the options out there or is everything pretty comparable?
I'm do some off roading/camping but am mostly on the road and don't want to give up towing ability.
Looking for any advice or recommendations.

right now it has older Fabtech Dirt Logic 2.5s (Blue) on the front from previous owner and the cheap white Fabtechs on the rear.