Not sure about the sedan, but on the coupe the front arms will tolerate a modest lowering with only slight negative camber and minimal/insignificant inner tire wear if you get aligned after the fact. In the rear even a modest lowering will require camber arms and ideally toe bolts—again, at least on the coupe.
I’ve been down both roads, starting with springs and shocks—don’t do just springs, your ride will be terrible, especially with 10year old shocks. Then, if you go springs and shocks and perhaps new rubber mounts etc at the same time, maybe even new top hats if yours are rusted like mine were, you are approaching the cost of a good coilover set—the Fortune 500s. Go to Luke at THMotorsports and he can get you the full Fortune 500 set up for around 1100 shipped. A good set of springs and adjustable shocks will run you that much or more and you will have no control over height.