You bought the Ranger because of excessive engine noise in the Grand Cherokee. Now you want to do a SAS to convert to 4wd like the GC. Then you want to install the GC's drivetrain (much better options BTW) into the Ranger. Finally you want to convert it to front and rear coil springs to ride more like the GC. Face it dude, you want a Grand Cherokee for a wheeler/mall crawler.
I suggest that you leave the Ranger stock for now. Use it do do what ever you need a truck for. Take the money that you were going to spend on building and modding the ranger like you have in mind and put it into building the Jeep. The Jeep is a capable platform if done right. For the same $$ you can do more to it, it'll be easier and cheaper to fix and build, and from what I read you'll be happier with it. When it breaks, you've still got the little 2wd 4banger Ranger to get around in and fetch parts with.
This
If you want to do all that to your ranger, it will cost more money then it would to fix the engine in your Jeep. But just in case you still want to make the ranger 4x4, here is what I think. I would drop the ABS idea, I believe your truck, being an 89, only has rear ABS (RABS) anyways, so it could be a whole new mess to gut the original system and install it from the Jeep. It can be done, anything can be done with the right amount of money and time, but its not worth it in my opinion. I removed the RABS in my truck, and my brothers to save $120+, and I have never looked back. If you go Dana 30 SAS, then the best axle is from a XJ Cherokee 1991-1999 without the CAD (central axle disconnect). It comes set up for coils. Lots of people have done this exact swap, so there is a lot of info out there to learn how it can be done.
Like JoshT said, the transfer case set up you are looking to do would be called a divorced transfer case set up. Once again, it can be done with the right parts, money, and time, but I don't think you have the right parts. The parts to do that are getting harder to find, and can cost a lot more then just using the ranger stuff. Plus, running divorced takes up more room then a married set up, and on a ranger, there just isn't enough room for it to be practical. If you want it 4x4, I would do as I said earlier and swap the transmission for a 2.3 4x4 one, or if you are comfortable with transmissions, find a much more abundant 3.0 4x4 one (not a 4.0, they have different ratios, and the 2.9 is a whole different tranny) and swap the main input shaft and tail housing over to your 2.3 tranny, making it compatible with a transfer case from any 4x4 ranger. I would find a manual t-case for the swap, unless you can figure out how to wire the shift motor on an electric one, or don't mind climbing under your truck to shift into 4x4.
On to the rear of the truck. I personally would not put the jeep's rear axle under my truck. If its the Dana 35, which I believe it is, then it is fairly weak, and probably weaker then the Ford 7.5 you have on the truck right now. If anything I would put a ranger 8.8 with lower gears (bolt in swap) or an explorer 8.8 if you can weld. You also get disk brakes with the explorer 8.8. The 2.3 only puts out around 100hp on a good day, so gears are where your power will come from. Like JoshT said, coils on the rear would be a big pain, and probably cost a lot more money then It's worth. I would do the chevy 63/64" springs as they give more lift and flex, but require some non bolt on work, or swap over explorer springs (bolt in) for a couple inches of lift.
Its honestly a lot of work just to put the axle in the front and getting the 4x4 usable. If I had known I would have wanted something with 4x4 2 1/2 years ago, I would have bought me a 4.0 4x4 Ranger, stuck a 4-6 inch lift on it with 33" tires and called it good. But being in high school, I was looking for good gas mileage, and cheap insurance. I've done so much to my truck, that it is more practical at the moment to do a 4x4 swap to it, rather then sell and buy a new truck. Plus I'm pretty attached to my current truck.
This is just my .02 cents, you can of course do whatever you want
That's what makes this hobby great. Someone always had to do it first.