1.Buy your Brembo rear calipers 4 PISTON BREMBO for "HOLDEN COMMODORE REDLINE, HSV ,G8 GXP ,SSV ,SS BIG BRAKES "
They are listed everywhere (you can buy them as a kit with pads and caliper bolts) if not below are part number for any part place in Aus
2.Rotor choice is as follows
-HSV -Holden Original Equipment (VE HSV 350mm Rear Rotors) $900.00 plus per pair "Genuine"
-DBA 42031/DBA42031S/DBA42031X/DBA42031XS. $480.00 per pair aprox
-RDA7376 type rotors $200.00 per pair aprox
-3H Rotors 42031-L , 42031-R Very Good Rotor $280.00 per pair aprox
3.Rear Caliper Bolts ,Holden Part Number GM-92139080 $35.00 set of 4 , Use the Genuine GM Bolts and you will sleep easy at night "Dont buy the HSV ones for $120.00 + ,HSV are rip off merchants (They are the Same Bolts)
4. Use a quality 4 Dot or higher Temp Brake fluid
5. Pads AC-DELCO PRO DURASTOP 17D1053M ,they also carry Brembo full Race Pads and many More , Ferrodo , Just ask the guys about the 4 spot Rear Camero Brembo Pads
Last thing is you will have to Frankenstein the Rear Brake dust shields ,trim off the curved lip off both , re-size the opening where the caliper will sit in,and you are done