Hey, redrock I've done a couple of springovers with different vehicles (inc 2 YJ's). I helped a friend do one a few years back using the RE kit and it was pretty straight forward. They do flex like crazy, but you'll need to use a sway bar w/ diconnects if you want to drive it on the freeway at all. You will also need a rear traction bar of some kind because of the increased spring wrap. It seems like the front springs sagging after some hard wheeling could be fixed by lowering the front bumpstops a little. You will also need longer brake lines. I think the biggest issue is the steering. To really do it right you will need to invest some time and $$ figuring this out. I have seen everything from high steer systems to bending the drag links (yes I have done this, but I would'nt do it now) When I lifted my wife's YJ I decided to put coils in the front and use Ford radius arms. So I just found a Picknpull D44 for it. One reason was because it made the steering a no brainer. The other was because the radius arms acted like a sway bar so it feels (and is) 1000% safer than any other Jeep I have driven with a spring over. I can even say that it handles better than any TJ I've driven with similiar lift.(probably because of the 'rear steer' effect that rear four links have. In the rear I redrilled the spring perches and moved the axle back about 1" (every little bit of wheelbase helps) I added one extra leaf to the pack and it is holding up fine. I would not have felt safe about my wife driving her Jeep with any other spring over. See if someone will let you take their SOA Jeep for a spin before you decide what to do.
Here's a pic of her Jeep- It would flex better with a wristed arm
Here's a pic of her Jeep- It would flex better with a wristed arm