One thing that everybody looking for "better" stopping has to realize is that the tire is a MAJOR contributing factor, particularly up front. It doesn't matter if you have six-piston Brembo brakes with a 15" rotor and carbon-fiber pads, when all you have on the rim is a bicycle tire. The "wimpy" stock brakes are more than enough to haul the car down from speed quite nicely. Once the threshold has been reached where the rubber meets the road, however, that's it, you're done. You CANNOT brake faster or more aggressively if your ABS is kicking in due to tire-slip. The rest of the upgrades are all about durability under repeated braking. Larger rotors will help dissipate the heat generated by repeated hard braking. More aggressive pad compositions will tolerate higher heat before glazing. DOT4 racing fluid can absorb more heat before boiling. Larger calipers will allow more clamping force, and the SS lines reduce expansion to direct pedal force to the caliper, but NONE of it actually increases the ability to stop the car in a shorter distance. In fact, larger rotors can actually increase the stopping distance, as there is can be a corresponding increase in rotating inertia.
If your complaint is brake-fade related, i.e. the third or fourth hard stop in a row just doesn't seem as firm as the first, then you need to look at heat management. If you want to stop in a shorter distance than you do now, then you need to look at tires, not brakes. Of course, with uber-sticky meats, you can now easily overheat a bone-stock brake package, but that's the "supporting mod" paradigm all over again.