For fluids, the trans and t-case both take ATF+4. Personally, I use it in the power steering too, even though the book says not to.
I run 75W-140 in both diffs (recommended by Jeep if towing), rear needs LSD modifier if yours has an LSD.
Coolant is old school green, although if you give the system a good flush first, Zerex G-05 (also Motorcraft gold and the Mopar pink HOAT stuff) is fine to use as well.
For engine oil, I feed my 5.9 whatever 5W-40 HDEO is on sale that day and change it every 6k miles. Those engines aren't particularly hard on oil, so anything of appropriate viscosity and changed before it's used up will do the job.
As far as the t-case itself goes, I'd run it until the VC fails and then swap in a 231 (it's a better case than the 242 a lot of people swap and it's 20 lbs lighter than the 242 and 249). I find the 242 fulltime mode to be worthless (it's an open center diff) and it doesn't shift nearly as well as the 231 does. The 249 is quite strong and just works though, so I wouldn't replace it until it fails.
If you google around, there's a procedure to adjust the steering box. I'd do that along with replacing whatever tie rod ends, etc. are worn and see what it gets you. A 1/4" or so of play is normal even right out of the factory.
I wouldn't plan to lift much for towing, maybe a set of the OME springs and appropriate shocks. That'll get you around 2 inches and firm things up a little. Check on the condition of control arm and track bar bushings while you're doing the lift. Adding adjustable track bars isn't required at 2 inches, but it won't hurt (especially if your stock track bar bushings are worn).
If you replace the front track bar, here's an easy upgrade: JKS track bar for a WJ and the Rusty's double shear track bar bracket for a ZJ. Basically the same as the Kevin's Offroad track bar upgrade but with a better bracket and for half the price. It bolts right in, only thing is you might need to trim a tiny bit of metal off the front of the driver's side coil bucket on the front axle to avoid contact at full suspension compression.