I'm not that familiar with suspension so any advice is greatly appreciated.
I have a stock 2008 SE sedan 2.0L with a ride that's not all that great. I'm also looking to lower a little with eibach prokit and possible koni yellows. I know its a preferred setup for many, but should I install just the prokit springs on a stock setup or with koni yellows as well?

Iv seen used koni yellows but I figure, that if I'm replacing anything it may as well be new and not another used part,

Looking at used prokit from a coworker as long as their 5545.140 I believe for the 05-09. Will the used springs settle the same as new springs?

Also I'll check out jimmy @ SP for the install and follow with alignment. many happy reviews about jimmy

Rims coming next season, thanks for any advice/ suggestion.