Lots of good advice above. I'm heading to Rimrock on the 12th for the day to set up camp, then will return for a couple weeks a day or two before big bull opens and remain till end of season. If I get there early enough on the 12th and if my health allows me to get the tent up early enough, I'll be testing some of the easier trails with the rig till around 4:00pm. You're welcome to stop by camp as I'll be wheeling for the duration looking for elk. Only one cow tag in camp, rest of us are spike only unfortunately.
There will be plenty of wheeling "Rimrock" style if you're up to it. Expect breakage and body damage at minimum however depending on conditions. All pending my health allowing the trip of course.
One thing that hasn't been mentioned is once you read all that stuff, use the calc, THINK you have it all figured out, you'll then move to start burning in your mounts. At that point you'll discover none of it works and you're left to deal with what you've learned from the above vs. what actually fits in your TJ's frame constraints, with the axle limitations, the body, fuel tank, steering, etc. and whatever else you feel needs to be kept or eliminated to make it all work.
I had a good plan on paper for my rig but ended up changing most of it due to space limitations. It still looks good on paper, but not what I'd originally planned. The thread on Pirate posted above, and many other threads as well I'd searched over the years all pointed to similar directions. I made due with what I could fit. I knew I wanted up travel in the shocks, I knew I wanted 12" travel shocks with 6" up and room for more if need be, I knew I wanted as much clearance as I could realistically gain and I knew I wanted it to behave on the street yet remain planted on the steep nasty off-camber hill climbs we have here all over WA. On paper I'm about a 72% AS with a slightly negative neutral roll steer. -0.0xx if I recall??? Forget exactly. My rears are I THINK 6 degrees, my fronts about 4 degrees-if I recall, I forget exactly. Rear uppers are parallel to ground 0 degrees and I can't say on the 3 link front, I just put it where it fit. I think I have around 6-6.5 VS at the frame and around 8-8.5 at the axle on the rear, my front 3 link is all but totally parallel with the lower.
What I've learned is I don't know jack about doing this type of thing and didn't know jack about suspensions before hand either. I THOUGHT I had a good ride before, but knew there were several things that I THOUGHT could be improved on. Keep in mind I'd been through 3 prior suspension swaps. This was my first REAL build. I retained the same 3" springs I'd had for a few years that are well used yet stuffed a 12" shock under them and realized a solid 6" of up both front and rear but actually have room for about 7" in the rear and 6.5" up front. In terms of handling of the rig, it is FAR better than anything I've ever ridden in prior. This is the best it's ever been on and off road. It is firmly planted over the rough washboard gravel roads just getting to the trails at nearly double the speeds I'd been able to achieve prior but I'm certain much of that is due to the custom tuned shocks from Wayne. The combination between shocks and suspension design is worlds different than anything I had pre-packaged prior. It's planted now where it broke loose before, and remains planted at nearly double the speeds-at least to the point of what I'm comfortable driving anyway. Meaning some gravel rough washboard roads that I was lucky to hit 20-25 before and would be fish tailing on, I'm now hitting speeds of 50+ planted and braking for the turns. Is it design? Is it shocks? I believe it's both but I can't say for certain as I have no experience with any other custom design nor any other custom shocks and tune. I couldn't tell you what difference I'd feel in the seat with 65% AS and -1.5 understeer, nor could I tell you what 78% AS with +1.5 oversteer would feel like. I'm coming from the last at a measured 172% AS and 12 degrees over steer so I have a good idea of what direction it would lead, but no clue on the "perfect" setup or if there even is one. Again, space constraints will dictate what you can get away with and how far you're willing to cut things up. My frame is cut in multiple points, notched in some and boxed in others, my engine mounts are modified, truss cut, crossmembers cut, track bar mount ground, track bar gusset ground, gas tank and skid some 4" over stock and back, etc. How far are you willing to take this??? My rig is a dual purpose that runs both street and trail and it's the best it's ever been. With all the prior suspensions I'd had, I always felt there was something "more" and knew immediate things I'd wanted to correct. With what I have now, I'm left wondering what "better" would be and struggling to find anything that really needs changed. My direction is shifted now towards better tube work, custom seats with harness and safety stuff. I have no clue at this point what I would change in the suspension if I did it over. Likely nothing at this point. Is it perfect? Probably not but it works for me, I'm happy and that's what counts.
Some very generalized basics-
Cut and relocate your spring perches to straiten the rear springs.
Outboard the rear shocks-yes, that includes frenching the frame in addition to moving lowers. Lowers only won't cut it.
Optimize shock travel with whatever length you want to run-shoot for 50/50. With your 4" springs, I'd be certainly running a 12" shock with 6 up and 6 down without question. You can try for more, but with a good 4" spring, you'll be un-seating before the shock is extended and wasting travel. 12" is about the practical limit. If you need springs, Currie is an excellent choice. Shocks-pick your poison but I will say the Fox 12" remote res 2.0s with Waynes custom tune is unbelievable. I have no clue how comparable Kings would run. Only Kings I've experience with were coilovers and I was never happy with the rates on them despite all the changes on that particular rig. It's not a fair comparison.
Uptravel IS important, find it.
Anti-Rocks are your friend. Use them-front AND rear.
Do NOT skimp on the parts used for this-not in the joints, not in the links, not in the shocks. Buy GOOD parts and you'll only have to do this once. Skimp on the tunes and disco lights to get good quality suspension components under the rig where it counts. This will pay off later with regards to the bacon and boobs.
Above all else, Have Fun!
Best of Luck,