I live in Central CA, not far from Doug Whisenant (whizco) in Fresno...
Unlike most VMF'ers, I'm not active in the hobby and spent the better part of the last 3 decades, when in a Mustang, in the race car
, as opposed to going to car shows. So, I have lots of experience to offer, particularly on drivetrains/chassis and racing, but little else.
My D-coder's chassis is still completely stock with factory power steering and manual drum brakes. The swap you desire (discs) is quite feasible on our cars and is similar to that on a 65-66. Many VMF'ers have done this swap and information and links should be in abundance in the archives. Just use the search
feature. Some have used Ford parts (mostly Granada) and some have used aftermarket (SSB and others) parts for the swaps. You can do front and rear, depending on parts used, for anywhere from 600-1200 complete, last I looked. You'll want to consider power assist if you don't have it, with discs, so factor that in as well. For an example of the process, please read this article
There are a lot of VMF'ers in the Bay Area, Napa valley and Sacramento areas so, if you have occasion to work in that area again, put out an APB here and meet up with some of them if you have time...they're great folks..
If you have further questions, feel free to ask!