What are you wanting to do? You should get better braking by just changing pads and installing braided lines. If you want more, look at Brembo. They have some of the best brakes in the world, if not THE best. Like any system, every component part is necessary for it run at its best. I have a bike with bremos, and if the wrong type of pad is on there, the brakes have no feel and suck, though still stop quickly. With the right pads and braided lines, they are awesome. Set up your stock front brake, it will cost much less. If you are not satisfied, then go for new calipers, rotors and master cylinder. But you had better do it all at once to make a complete system change, so you don't have miss-matched stuff that doesn't work together at all.