Builder died

The gentlemen that was building my 69 Dart GT passed away expectantly. I hope he is in a better place.

I bought his project from his estate and have no information on the parts he used for the build. It was a 6 cylinder car that he changed the k frame and now it has a 360 cid. He also converted the front to disc brakes and large bolt pattern hubs. I have the new routers he put on but do not have the calibers, pads, master cylinder or the front flex lines.

Any advise on where to start when ordering these new parts. Are Mopar disc brake caliber's interchangeable on most models?

I would like to finish his car to honor his memory but need some help as this is also my first Mopar.

Thanks