Give the man a cigar!
Bob's right on...
Just a few pitfalls you may encounter when making such a change
#1) '69-'70 rotors ARE NOT readily available. They are 12" DIA and are hard to find in usable condition. CPP is the only source that I've found for new ones, and they aren't cheap
#2) Master Power makes a sweet booster/master cylinder combo that works really well. Just make sure that you adjust your pedal height accordingly. Changing to a disk brake setup requires almost twice as much pedal travel and you will bottom out if you dont make this correction.
#3) If you don't get your front end re-aligned
after changing spindles, you will be eating front tires... Guaranteed!
Good Luck!
Rock