Well, there area few things you can do, theres an upgrade availiable from dreamspeed for the front and rear sway bars, front nad rear stut braces, you can always do a drop kit for it, some nice coilovers nad koni shocks seem to be the way to go, then theres awlays new rims with performance tires. It kinda all depends on your budget, i would recomend starting with the front strut tower brace and soem better tires.
I have KONIs on all four corners, rear swaybar, and upper braces front/back. Lowered with Suspension Techniques springs. KONIS are set 1/2 stiff in the rear and 1/4 in the front. The car handles like its on rails.