I'd have to agree with the previous post regarding keeping your drum brakes. Not saying that the discs aren't obviously superior in stopping power, just not saying the gain is worth the cost. More than likely the upgrade in braking he'd get from a shoe, hardware, drum, and wheel cylinder replacement would be more than adequate and about 1/20th the cost and labor of a conversion. He probably wouldn't have to change the master cylinder but he'd have to take into account brake force proportioning and most importantly ABS which can get expensive fast.