The RC 4.5" short arm has treated me pretty well so far. There are a few things you will bang your head against the wall over if this is your first lift though. In retrospect, I would have also:
replaced steering (instead of waiting until this week, a year later, to buy JCR 1-ton)
serviced/replaced steering box (if you're going to do it, do it now, otherwise check to make sure everything is in good order, because now is a good time to do it)
replaced leaf bolts into frame (yeah, I know, but mid state bolt and screw didn't have them)
replaced UCA bushings
planned ahead with either BPE's or ideally the (overpriced) JKS x-over rear shock mount
stainless extended brake hoses (optional, but ideal)
DISCOS!!!!! (and optionally a removed rear sway bar, if you got new packs and not just AAL)
As always, torque and lock-tite to spec, and check check check the u-bolts for proper preload when torquing to prevent a sheared retaining pin and thusly shifted (4" rearward) main leaf which I have experienced. I do believe RC will be remedying this for me on their dime as well. Enjoy.