you wont see a big flex improvement with the budget boost. if you want great flex (read as in alot better than stock) then you have to swap comtrol arms. i had really good luck with the rancho rockcrawler 2.5
the control arms allow boatloads of flex but retain the handling characteristics of a near stock tj. plus, there are no heims or "johnny joints" in them to break or wear out. the one downside it that the bushings on either end need to be rebuilt every couple of years and it costs about 50 bucks per arm (200 total)
the kit as delivered will clear 32s easily. to get to 33s you really need a 1" spacer and a sye kit. of course gearing will be needed to run 33s as well unless you no longer want to use 5th gear