First off, take a look at BDS. To my knowledge, they're the only other MFG that have a lift in that size, and that have a good rep. around here.
As for the adj. t-bar, I say go for it. The bracket is made for a certain height. As in, to keep your tires aligned side to side in the rear, you'll need to get the exact lift that the bracket is made for. So, if you buy a 2" lift, and something were to happen where you end up getting too much (2.5") or too little (1.5"), your results may not be very good. It may not be noticeable, and probably isn't most of the time, but the tires may still be off because the bracket is a one size fits kind of thing. The adjustable bar will allow you to adjust it no matter how much you lift or how much you settle, and will be necessary later on if you go higher or add spacers for adtional lift or to fix the rake of the jeep.