I recently purchased the 6 lug disc conversion from CPP, it was any easy install as well as the undercab double diaphragm booster. They offer a kit with discs, calipers, hubs, lines and bearings. You will have to make your own brake lines, they only offer a firewall mounted brake line kit.
As for ease of installation, I would recommend the kit. Summit marched CPPs eBay price of $699.
https://www.summitracing.com/parts/clp-5559cbk6hk