My buddy had a set of the Pro-comp MT's on his 1/2 tone chevy and hated them in anything but sand and dry pavement. The thing was downright dangerous in rain and snow.
Yeah they were, they arent made anymore. The RCD was a couple hundred more than the Superlift when I was lift shopping but I wanted the extra 1.5" and the bilstein coil overs was a big selling point too. Plus not having the huge torsion bar drop brackets hanging down under the is a plus.
The kit comes with AAL's and shackles to lift the rear, just ask the seller if those components come with the kit when he sells it. Also make sure he includes the pinion angle correction wedge shim also.
Coopers are nice too but when I was tire shopping the Coopers were more than the Bfg's were. Price was one main reason I went with Firestone Destinations. My 18's are expensive to put rubber on and the 20's are going to be worse. Id milk as much life out of those Bfg's as you can.