Joined: Nov 2007
Posts: 3,549
Likes: 1
From: Somewhere between heaven and hell
Bikes: '09 Jamis Komodo, '09 Mirraco Blend One, '08 Cervelo P2C, '08 Specialized Ruby Elite, '07 Yeti AS-R SL, '07 DMR Drone
As long as your weight is in the right place, you shouldn't go over the bars no matter how powerful your brakes are.
Most people put the same brake front and back, unless their frame isn't disc compatible or something. You can run a bigger rotor up front for more stopping power if you want.