EF coilovers and q about spring rates

I think a few of you have installed EF JDM full coilovers on your DA and I was wondering how much work in involved as well as opinion on ride quality of whichever coilover you got. Also, I was wondering if 12k in the front and 10k in the back are too stiff of spring rates to run on the street. I don’t want a backbreaking ride.