I agree with what half the people here are saying. I was looking at upgrading brakes, and I did. I did rotors, pads and fluid. My stopping power was MILES ahead of what it was previously. It was quite inexpensive too.
I would start with slotted rotors and decent brake pads first, give that a try. Then, if it's still not enough, buy some GTR Brembos or something.
Even a year after doing this mod, I was still under estimating my braking at the clubs motorkhana where we had a Go-To-Whoa. I stopped up short every single time...