I’ve been investigating this further and found that the MC and vacuum servo of a ‘92-‘94 Granada mk3 (facelift) will fit the Cosworth fire wall without modifications. The Granada uses a Teves mk4 ABS system that I expect can easily be swapped by a newer MK60 system.

For the ABS system I’m not sure yet what is best to use. The MK60e5 is the most modern system and should give the best performance, but it uses magnetic rings at the wheels. I found a list of both normal and magnetic ABS rings, so it’s not impossible to use the MK60e5.