I can source the other parts including the disc/rotors, rear parking brake assembly and brake hoses myself. Have in fact already purchased some Pro RS stainless steel braided brake hoses. The Pro RS branded braided hoses are claimed to be sourced from Eaton Aeroquip so should be decent quality. Shame about the Goodridge lookalike packaging though.
Anybody with leads on some decent N16 rear disk brakes please please contact me. Don't let my spiffy new brake hoses gather dust and feeling lonely in my cabinet..