Well, for the 02-05 wrx front brakes (the cheaper one) you need.
02-05 wrx front calipers and caliper brackets
02-07 wrx rotors
Brake pads to mach the calipers. I say this because the pads on the 02 wrx are different from 03-05. Depending on the condition of your old brakes and if you know what your doing, the swap should take a couple hours. I've seen it done in about 20 mins though