That is a lot of bad advice. No offense intended...
- Cherokee (XJ) springs are a lot softer than TTB lift springs, therefore you will get LESS lift and you will need a taller spring, although XJ springs are a good choice if you get the right ones (4-6" ones are not enough in some cases.)
- Leaf springs are not necessarily easier. There is just as much fab if not more so for the steering. "Because it's more complicated" is not a good reason to run a radius arm setup.
- D30 is STILL not a really good choice of axle unless, like I said above, it is free or close to it and already has the gears you want. Why do you think Jeep guys take them out? Hint - it's not because they're strong.
I don't know why it matters if parts are readily available when you're breaking shit all the time because your rig is under built.