As to replacing parts, before I bought new upper control arm bushings and upper ball joints, I would check the price on a new UCA with these parts already attached. It will save you a fair amount of work. I'm more of an e-body guy, so I'm not sure of availability/price for a complete assembly but folks on this forum will know.
i don't know how else to word this, so here goes: this is a wonderful idea and could potentially save you money, if you don't care about the quality of the components in the arm or the quality of the arm itself.
i'm not all ma mopar made the best stuff since sliced bread, but having seen, held and installed aftermarket stamped arms there is a noticeable difference and the ball joints and bushings are straight hong kong phooey.
it might be a little more money, but if you rebuild the OE arms at least you'll know there's quality components in them.