I used the Teraflex shock extensions (P/N RST) - this part is very solid and durable. I didn't like the look of the Currie part because it is exposed to all sorts of possible rock damage and I thought it would get bent pretty easy.
I have seen these, and didn't like the way that the looked. Just some bent metal that wrapped around the old mount and supported the shock. I have/ had the Teraflex shock relocators installed on mine. I prefer the teraflex over currie because they are solid steel, powder coated, fit inside the original shock mount, have an additional bolt in the back to help stabilize them.
What size of lift are you using? I have a 2.5" OME lift and even with the wide OME shock canisters I get no interference at all. The technician at the dealer who installed it even rotated the pinion up a little which would cause even more potential for interference but there's nothing.
At max flex I rub the passenger side canister, just enough to remove the paint, but not enough to dent the canister, I am keeping an eye on that shock. I will reinstall my relocators when I roll the pinion.