If you are going to drop that kind of coin with upper arms and all, why not just do it right and get some Fox Race Series Coilovers. Not matter what, if you add preload to the OEM spring with OEM shocks, they will lose down travel and ride harsher, especially if you are offroading and need down travel.
I personally have been going back and forth with maybe getting a set of Icon Coilovers , rear bypasses and Live Valve delete. The only reason I am looking at the Icon as the King rear bypasses are so damn loud that they sound like you have a bunch of marbles in your bed when hitting bumps.