Rotors won't give you more stopping power, replace them if yours are warped. You can get them machined as well.
A cheap and effective mod is to run 99-04 PBR caliper from a GT or V6 IIRC. And a good pad. EBC, Hawk, Porterfield, all make good street pads. They will be pricey to do all 4, but that's what does the braking. If your pads suck, so does your braking system, no matter what you have.
And don't forget to change out fluid. Flush all the fluid with a good bleeding. ABS setup takes a bit to get everything out, so be patient. DOT 3/4 synthetic is what you want.