unless you are racing the car on the track, you don't need a complete brake system upgrade.
My suggestions:
1. Upgrade to Stainless steel brake lines to get rid of the smushy brake feel.
2. Upgrade pads in the front
3. Upgrade rotors
I have done the lines from Versaspeed and it was plenty. I don't plan to upgrade other items until the pads and rotors need replaced.