Unless you're going to race the truck I would stick with the Jag or conventional leaf springs. There are new leaf springs available for your truck that require no frame mods. They simply bolt in. You would have to modify the spring saddles on whatever rearend you chose to use but that isn't a big deal.
I haven't looked at the 4 link you mentioned but I can almost guarantee that some frame mods will be required. I always caution a novice to keep it simple on their first rod project. So if I was you I'd go with leaf springs, but good luck whichever way you go.
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