This is just my standard speech on steering, and certainly no offense meant to Iron Rock Offroad (I do like most of their products and have used some of them)
but I wouldn't go with that IRO kit. No way, no how. Here's why:
It has you drill out the knuckles for 5/8" bolts. On the driver's side... fine. It's single shear but it's a 5/8" bolt, too, so... fine.
On the passenger's side, you have *two* single shear heims that are stressing the bolt *in opposite directions*.
It has become "common sense" that the friction produced by clamping the heim joint to the knuckle is what carries the load
EDIT Which is mostly true but in highly stressed joints, like track bars and steering, it's not uncommon to see single shear mounts get wallowed out with time & use. Heck, even the factory double-shear track bar mount will wallow badly over time. I've heard a few reports already of the IRO kit wallowing out knuckles & becoming a major PITA to keep steering tight / safe. I suspect it's a matter of time until that's the conventional wisdom about the kit or about that style of steering.
JCR, Ruffstuff and Serious Offroad (and many more) sell "1 ton" steering kits that are all, pretty much, the same. On an XJ Dana 30, none of them are a great choice. The drag link frequently intercepts the tie rod at too steep an angle and too much of the steering force is turned into vertical force, causing the tie rod to roll before pushing / pulling the tires around. This creates a dead spot and there is no long-lasting solution for this problem. It just isn't well suited to most XJs (though it can work very well on some custom setups)
The Rusty's Tie rod, the Currie setup and the ZJ tie rod will all work about equally well for daily driving. Stength and price would both go Currie, Rusty's then ZJ.
OK, time to watch the Daily Show and get some news. Hope this helps and that I haven't had too many brain farts along the way, here.