X2. I'd pass on the second set, a modern single shock will work better than 2 oem's. The shocks listed above will work with a 4-6" lift.
25-101966: 15.89" compressed, 25.91" extended.
25-101874: 17.78" compressed, 29.70" extended.
As far as running them on a non-lifted truck, you would have to figure out the maximum compression of the suspension to be sure you don't bottom them out. One way would be to cut a proper sized rubber washer and install it around the stock shock stem next to the shock body. Drive around for a while, making sure to hit some bumps and dips, then measure how far the washer has moved on the stem. Subtract that amount from the eye-to-eye measure, then compare the results to the max compression of the Bilsteins. If it's within a couple inches I wouldn't do it, you gotta add a little fudge factor or you'll ruin your nice new shocks.