Well, for 91-94 Explorers there's quite a selection of suspension lifts available:
-For 1.5-2" lift there's coil spacers and Warrior shackles, ~$100. No new shocks needed.
-2" SkyJacker Lift which includes longer coil springs and add-a-leafs, ~$200. No new shocks needed.
-The 2.5" James Duff lift consists of TTB drop brackets, radius arm drop brackets, coil springs, add-a-leafs and 4 shocks, ~$400. Longer radius arms are available for $300 more. You may need longer brake lines.
-SuperLift 4" has TTB drop brackets, radius arm drop brackets, coil springs, new rear leaf springs and a dropped pitman arm, ~$800. Longer radius arms are available for ~$400 more. You will need longer brake lines and shocks.
-SuperLift 5.5" has TTB drop brackets, radius arm drop brackets, coil springs, rear SOA kit and a dropped pitman arm, ~$600. Longer radius arms are available for ~$400 more. You will need longer brake lines and shocks.
-SkyJacker 6" lift is rumored to be discontinued.
Then there's always body lifts. If you ONLY want to fit bigger tires and raise the truck a bit this may be your best bet. You also can mix a 2" suspension. and 2" body lift for 4".
I recommend figuring out what you want to do with the truck and asking lots of questions before spending one dime. Hope this helps...