seriously man, don't waste your time fitting big brakes, it doesn't need them! If anything, fit twin piston calipers off a corona, and a bigger master cylinder and booster. if you feel the need to spend money, then get slotted, vented discs from repco, they'll be about $150 each.
the cost of twin turbo's on a 4k far outweighs any desireable power output. get a 1ggze style supercharger, there cheap as chips and pretty easy to set up.