What you would need to purchase is a way to keep the rear brakes from locking up every time you touched the brakes. There is a valid reason they put the bigger brakes on the front. Unless you mean the 300GT rear brakes in which case, there is no point, they are the same essentially and don't have the E-Brake accommodations needed.
For the fronts, you need the calipers, pads, rotors(5 lug is easier to get) and the caliper brackets from from Garfield.
/brox