Don't skimp on suspension. It's basically what controls the contact your car has with the road.
Best bang-for-buck, IMHO, Bilstein shock absorbers, Kings springs. A full package will probably set you back around the $1500 mark. If that's beyond your budget, upgrade the shocks first (about 1G), then do the springs later. (If the shocks are leaking, they aren't working, so a waste of time doing anything else.)
Sydneykid has a group buy somewhere on the forum, do a search.