No matter what brakes you decide on, you will still have disc front and drum rear, so the master cylinder, booster, lines, dist. block, etc... do not need to be changed.
I doubt you'll need new spindles. Probably just a new integral hub/disc, which is how the cars were originally made. Some other kits might use a hub with a separate disc. I'd say there is a good bet that Cass (Dr. Diff) will have what you need, at a decent price too.
