Duster Front Drum/Disk Conversion Questions

I've been looking on Classic Industries for a disk brake conversion set. All I've done is confuse myself more, lol. I see all these options for electric, manual and power disk brakes (All ranging from $500 to $3000). I'm looking to use my car as a Sunday driver, not a race car. I will have a Big Block in the car (so extra weight is the worry). So What are the differences and what would you recommend as my best bet for front disk brakes? (I would rather try not to break the bank!) Thanks All!