Upon searching even more it looks like my thoughts are right. He's using Ford SuperDuty unit bearings, redrilling them to 8x6.5 bolt pattern, and the MileMarker locking hub kits he includes fit multiple setups including 99+ Ford. The only thing I haven't figured out for sure yet is if the stub shaft included is just a stock Ford stub shaft or if any of it is custom. I have a friend who has a Ford SD front axle laying around he's planning on converting his truck to 4wd so when I have time we will tear into it and find out.
Timken SD unit bearings are $173 ea on RockAuto
MileMarker 449 locking hub set is $157 on PartsGeek
Stub shaft yet to be determined $100 to $200 each online
Video describing parts
https://www.youtube.com/watch?v=xmDcYszX--4
Video of customers install on his youtube channel though uses the same stub shaft U-joint as stock.
https://www.youtube.com/watch?v=8yBNpBiJoIo
http://www.THERAMMANINC.com kit $1700