Sbp to bbp

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 Probably just a new integral hub/disc, which is how the cars were originally made.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.