Rear suspension questions

[redfunny123]

Hi a newbie to the forum so dont bite!
Got a few basic quastions about the rear suspension of the roadster:
I'v got the book by chris gibbs but the part about the rear hubs etc is in parts, a bit skimpy so hence how iv ended up here . Firstly, as i have no whole donor vehicle, can either the granada, scorpio or sierra hubs be used to bolt straight onto the rear uprights, if so do the corresponding calipers have to be used IE sierra hubs with sierra calipers. Also what disc diameters would have to be used and would they be drilled/ grooved. In a nutshell im just after a very basic disc brake set up, nothing spectacular with vended discs etc.
Any replies will be much appreciated, thank you