I bought vt/x/y/z control arms from wreckers, removed my vs control arms and swapped the handbrake components over. To get the handbrake backing plate off u need to remove the hub, when the hub is removed u will need to replace the wheel bearings. The vt and vs backing plates have the same bolt pattern onto the arm but they use different bolt (I used the Vt bolts with the vt backing plate onto the vs arms)
Back the vs handbrake off under the car adjustment all the way, then u can hook the cable into the rear wheels and adjust as needed.
So when u take off my rear rotors and calipers it looks like a vt set up. The caliper mounting bolts are common across all models.
Cost was $50 each arm second hand, bearings are about $60 each genuine.
There is also a cage that goes around the nut that holds the hub on which I replaced these are $12 each genuine.
Bit off time and the result was great. Great handbrake feel and many breaking options from standard vt rear rotors to all HSV options. I also replaced control arm bushes with nolathane items and a camber kit.
Have not driven car yet with new brakes.