Thanks for the quick reply! The car actually has the stock R32 rear subframe with a HICAS delete.
I somewhat figured I may be the only one with this setup, but figured it would be worth a shot to ask here! Unfortunately, we didn't get Skylines here in the states, so finding GTS 4 lug rear hubs, rotors, and brakes may take some time.
I actually still have all of the OEM 5 lug Type-M brakes, hubs, rotors, etc. I'm keeping the car 4 lug to keep the period correct 15" Longchamps on it!