What are your plans for the car? Drag racing? road racing? or just a nicer brake setup?
Some people out vented/ drill rotors in the rear and a better pad compound to help stopping.
I have seen what looked like 94-04 cobra front brakes on the rear of our cars and they added a smaller parking brake to utilize the parking brake feature the car came with.
You could swap cobra rear brakes onto the rear, pretty much a larger vented rotor, mounting plate, and larger caliper bracket is pretty much the swap
There is a $1000 plus rear kit from baer or wilwood for a 12" rotor and a larger rear caliper. brake lines are extra
Or you could do the Baer rear 13" rotor upgrade. I went this route but i have been able to try it out yet. So i do not have a full opinion yet on the kit. Installed really easy compared to the cobra rear brake swap. The cobra swap you have to pull the axles. it is more messy than harder, than just adding the baer rear kit.