Why would your control arms be too short? You have an off road, with 2" levelers... shouldn't be THAT bad.

Put the new track bar on your truck. Measure the distances from the outer edge of the tire, to the inner edge of the fender well. Use the same point on both sides of the truck. find the difference. That's how far you will need to adjust your track bar.

Really, you are making it far more complicated than it really is. This is going to turn out to be one of those "That was f'n easy" moments.