^What Chris said. You'll need to regear front and rear regardless. For a gasser, general rule of thumb is 4.56 for 35s and 4.88 for 37s to get back to stock feel. 4.88/35s or 5.13/37s for a little extra power/get up and go but a couple hundred more rpms on the highway. That and a good tune from Black Bear Performance would go a long way without all the trouble of a SAS.
I'm sure someone on here can chime in, but I would check out Pirate4x4 for all the details of a SAS for your truck. It's pretty damn involved and your truck will be down for a decent amount of time for that, even if a shop does it. There's no "kit" for a solid axle swap, but places like Off Road Direct can point you in the right direction. You basically have to piece it together tho, from springs, brackets, steering, transfer case, driveshafts, sensors, brakes, etc etc. As I said, there's quite a bit involved