Raybestos RC4176 Caliper sourcing

I am in the process of gathering the necessary parts to upgrade my 68 Dart GT from front Drum brakes to disk brakes.
I am fitting NOS parts so the conversion looks like it was factory fitted.
I have all of the pieces required for the conversion except a Raybestos RC4176 Caliper (I have a Raybestos RC4175 so I need the matching RC4176)
I have tried Rock Auto but they never seem to have the Caliper in stock. :banghead:

As I live in New Zealand, it is sometimes difficult/expensive to obtain parts and get them shipped to me. Along with the freight costs it is too expensive to supply a core exchange so I have to pay the top price.

Can anyone suggest where I can purchase the Raybestos RC4176 (or even a FRC4176) that will also ship internationally.
:help: