My brother bolted my set of Pony rims on for me while I was stuck on the couch with a leg infection

He noticed the pass side rear spring was split clear through
It has not seperated yet and sits fine, but obviously needs to be replaced. So... I figure on a new set of springs instead of just getting another stocker. This is a daily driver so I dont want to lower the car, but would like to get some more handling.
Any suggestions??? I have a set of Monroe replacment struts up front, and will replace the original quad shocks too. I'm riding on some 245 50/16 Falken Ziex 502's