From what I've gathered in my own research the set up will have a lot to do with length. The shocks all come with predetermined lengths, fully extended, load height and compressed height. You'll have to figure all these when setting up the suspension. Most of the coil over kits will come with set up directions.
You will need to four corner scale the car to get the exact spring rate, guessing I would say 1000-1500 lbs total on the rear. LOL, you get me a couple sets of shocks and springs and I'll help you install yours. I'm actually doing my first four link car right now and learning some of this as I go. I've helped do one before so I have a grasp of what I'm doing it is just a lot of trial fitting to get it right the first time.