BRAKES!!!!
They would depend a lot on the use of the vehicle.
My HR30 PNV has over 250rwkw (about 340rwhp) more than most of us on this thread will ever have.
I have BNR32 GTR fronts (296 x 32 ventilated rotors) with Nissan 4 spot alloy callipers, the rears are standard DR30 2000RS (290 x 10 solid rotors) with standard single spot calliper.
Bearing in mind that a large proportion of the braking is done by the fronts, using slotted rotors and EBC, Endless or similar pad upgrade, you should find the braking more than adequate for all but the most extreme race conditions. S/S braided lines will also help, as they eliminate the expansion the rubber lines get under application pressures. Makes the pedal feel harder.
Z32 300ZX (280 x 30 ventilated rotors) are also an option, but in both cases, the offset of the front wheels has to change to alloy clearance on the 4 spot calliper.
My car is going to engineering with stock DR30 all round and after fronts will be modified to suit BNR32 GTR, because wheel spacers OF ANY KIND are illegal and very necessary to cater for the 4 spot calliper.
I am planning to use my car for Super Sprints & Hillclimbs and they will be the best I can get, for value.
Someone please tell me why I need bigger, but first go to the Jenesis site www.r30.co.jp and tell me where they say anything bigger than DR30 rears are required, and they have been racing these cars since long before we all got interested in them.