Now do you have any opinions about the rocky-road 4.5" lift. I was curious to know more opinions about it. I am especially Leary of the use of the front stock coils as the lift coils for the rear.
In my opinion I would stay away from that that kit IF you are actually going to take you jeep offroad. Once you get over a 2.5"-3" lift on a ZJ you are going to need adjustable control arms to fix any rubbing and vibration issues you will have with your axles and driveshafts at a 4.5" lift. They provide a t-case drop to try to "fix" the vibration problem but believe me it will cause you more headaches than anything else if you actually offroad the vehicle. Not only will it lower the "belly" of the jeep causing it to hang up on things, it also SEVERELY messes up the geometry of the already crappy OEM t-case linkage, let me explain... part of the t-case linkage mount on your ZJ is mounted on a bracket that attaches to your tranny and t-case, the other mount for your t-case linkage is mounted on a welded FIXED point on the undercarriage of your jeep. So if you lower your t-case say 2" like this "kit" would do and thus lowering one of the aligned mounting points, then you will severly bind up the already badly designed linkage for your transfer case. TRUST me on this one, I was also a "newbie" when I first purchased and lifted my ZJ and also thought I needed a t-case drop, but after taking my jeep out for the first time after the lift I quickly realized all the problems a t-case drop was causing me (not being able to fully shift into 4lo and back fully to 2wd all the way just to name a few) and promptly removed it, on the trail for that fact!!! This kit also does not come with extended brake lines which will also be a problem for you IF you decide to take your jeep offroad, on pavement you don't really need longer brake lines but once you get offroad and your axles start articulating then you will be stretching the limits on your OEM lines with a 4.5" lift, and that is certainly something you don't want to break out on the trail.
I am currently running a 5" lift with NO t-case drop and I'm only getting a very MINIMAL vibe when I'm doing 85+MPH in my jeep. I attribute the lack of vibes and rubbing on the fenders to the adjustable control arms being able to line up my pinion angles on both axles to minimize vibrations and push the axles away from the sheetmetal. Everyone has their brand preference when it comes to lifts so I'll let you decide what you want to get but I went with a full teraflex kit minus the springs (heard the springs were stiff) and opted for Skyjacker springs instead (heard they provided a softer onroad ride) but I've probably would have gone with Rubicon Express springs instead if I knew then what I know now. Heed this old adage, you certainly will get what you paid for if you skimp, whether it be ride comfort of offroad prowess. Swaping your front springs to the rear to get lift, well I can only give you second hand info on that since I've never personally done that on my jeep but a friend of mine that used to have a ZJ once swapped his 4.5" front springs to the rear to get about a 7" lift when he went to longs arms and he did NOT like it, he said the back end of his jeep felt "squirly" at freeway speeds and the jeep felt stiffer on the trail (realize the front springs on a ZJ are designed for just that, the front of the vehicle carrying the engine and what not and have a different spring rate than rear springs), he even tried "fixing" the ride by first heating them up with a torch to reduce the spring rate (did not work) and then even cut them down and used spacers to reduce the spring rate (also did not work).
Like I mentioned earlier I'm going to long arms here when I warms up enough for me to crawl under the jeep and weld all this stuff up but I did run short arms and 32's for 3+ years and it worked and flexed like no other offroad and onroad so don't let anyone tell you that you NEED long arms to be capable offroad with a ZJ... Once I upgraded to the 35's that was a different story and I needed to go to long arms to take FULL advantage of what 35's can do for me offroad. Hope this helps.
Fred R.