Actually, a ZJ is really easy to build, and it does not cost that much either. The nice thing about the ZJ OVER the XJ is that they are coils front and rear. If you want flex like you said, just put on some 3-4 inch long arms, with some 32-33's. STICK TO THE JKS! They are SO the best out there. They are greasable, and they are really easy to get on and off. Though I do not believe they make them for the rear.
WITH an XJ if you take off the rear sway bar, I doubt that it will make much difference, I have a CJ now (leafs obviously) and I took mine off and even with a hard yank on the wheel you really can not feel anything. I also have had TJ's and ZJ's and if you leave the sway bar disco'ed on the front WOW you can tell, and wow it is scary. REALLY easy way to roll an XJ on the roads, I knew a guy who totaled his because e yanked it at 30 mph and it rolled right over the stupid duck he was trying to avoid.
So yeah, I personally think that the ZJ is easy to build in comparison with the XJ, and less cutting required. I also personally recommend the JKS. I only had one problem with all of the JKS systems I have installed (six so far) and that was my fault as it turned out, but the JKS guys shipped the replacement parts free of charge, had them in just a few days.
And the ONLY time a jeep is “no match for a yota” is when you want to haul a lot of manure around, given that they are not well adept at hauling crap with them…
Cheers
Brian