stock brakes are fine for daily driving... if you're trying to hit the track though, you'll be seriously let down... I don't care how much drilling and slotting you do to stock brakes, they are still gonna fade something serious on you. Drilling is for looks more than anything. Slotted will help, but not as much as other options. by the time you pay to get stock rotors slotted, you might as well have gotten z32 rotors re drilled for 4 lug. Pick up some reman'ed z32 calipers from the parts store and you're good to go. Then you can work on the little stuff like a bigger master and baces and lines and all that jazz. when you really sit down and look at the cost of just upgrading versus tweaking with the stock stuff you'll quickly see the advantage to just doing the swap...
but that's just my 2 cents...