The Kore kit is nice, but definately pricey. It's not so much a lift kit as a suspension system designed to take some abuse.
I was running H2 takeoffs, 315/70-17 with no lift and as RMC/AMC mentioned, very little rubbing, and only at full lock, usually in an off-camber situation.
With my current 35's, I still get a little rubbing, but that's from the tires hitting the shock reseviors. I really need to rotate those back.
I have no complaints about my Fabtech lift. It works/looks good. I wish they did something more than just blocks for the rear. I added an extra block to level the truck better, the standard lift left it a little nose high.