The sway bar isn't going to effect the rough highway ride, so you can eliminate that. Do you have a lift dialed into the sway bars. Using them to lift a light weight rig usually results in a stiff ride, as well as the skyjacker 2" lift springs you have in the rear.

What was the tire pressure set at before you let out some air? What type of tires are you running? I set my tires at about 2.5lbs under what I run them at so once heated up they are at the right pressure.

Since you think teh shocks are bad, replace them with shocks that match the lift you have now, i.e., 2" longer than stock. If you are looking to spend about $200 on shocks, the sensitracs are about the bets you can buy for ride quality, if you are looking to spend about $100, Napa has them for about $25each. IIRC the T100 rear shocks are about 2" longer than the trucks, so they will work for the rear, i don't remember what I used on the front, I had the parts counter person look up the stock size in the book and then find one that was 2" longer for the ball-joint spacers I run in the front of my '91.

You could also consider replacing the sway-a-ways w/stock and use ball joint spacers instead.

How many leaves did skyjacker use in the replacement packs? If only used the same as stock, you could rebuild the pack using longer springs, use longer shackles to flatten out the springs some, or through a couple 100lbs of weight in the bed.