Upgrade rear axles, and disk brakes in front.

Hi all, I'm looking to upgrade my rear axles (just the shafts if I can) on my 1968 dart 270, the goal for this is to get away from the 5 on 4 bolt pattern, also I would like to upgrade to disk brakes in the front. My question is what would be the. Best donner car 2 get these parts from?