Since no one else has posted I thought I would through a little of the info I have as I did kinda the opposite thing. I took stock disk brake parts that were originally on a 70 mach 1 and put them on my 67.
Proportioning valve will need to be changed. My suggestion is to use an aftermarket adjustable one. Its just so much simpler.
Mastercylinder. You will need one for a disk brake car.
Pedals, you will need to convert the pedal to one from a disk car if I am correct (this is necessary for 67/68s).
Another option is to go with nonpower disks and use the 73 non power DB MC from a maverick. This will bolt right in, but will require some brake lines to be made to get the fittings to work. (I went this route because I didn't want to pony up the cost of the new power booster, mine works really nice with the manual disks)
The spindles from the 70 bolted right up to my 67, I would guess the 68 will bolt up to your 69. You will need to use the tie rod ends from the car the spindles came from.
(I cannot tell if you are asking if the spindles on your car will work with the disk brake stuff, but that answer is no. You will need to change the spindles over)
Wheel fitment is not a problem in this swap (65-66 cars rims will not bolt up because of clearance issues)