planning to put gsr brakes onto my eg. what i got so far are(correct me if i'm missing somthing) both front knuckle. calipers, calipers bracket, rotor, pads. proportal valve. and i'm thinking of getting a brake master cylinder too but dont know if i really need it? would it be big difference? anybody? thanks.

 

if you have a EX or si you'll have a slightly lower pedal but not by much. If you have a different trim level, i would suggest replacing the master cylinder.