The youtube video has an email address of the guys that did the conversion. I'm sure they can help with the parts needed.
I have thought about this swap to. Another thing no one has mentioned. The 10 speed can be shifted without the use of a clutch, with a little practice. Using the clutch for starts and stops only. That would cut the wear of that whole assembly dramatically. Also, the 10 speed has a short shift when empty. Start out in second gear. Then hit high range, and go to Lo gear. Then finish the shift pattern out. It works great for 10 wheel dump trucks. 1 ton pickup will never hurt that transmission short shifting.

 

I know they put 6bt's in medium duty freightliners that use fuller transmissions. I think thats where I'd start.