Standard R32 GTR brakes are not realy up to competition standards.
Best used for stock or lightly modded car.
I would aleast try to find a set of Brembo's from the V-Spec R32's or get R33 or R34 ones, if not then start pulling out the $$$ and get some Endless, Project Mu or K-Sport setups.
I would say brakes are one of the most important things to upgrade when doubling the kW's of your engine cuz you go faster, you better stop quicker.