The first one I did was just a mashup of the two you have on hand. A little cutting and welding, good to go. You'll need some kind of support bearing if you don't want to listen to the ujoint bouncing off the headers every time you turn.
The ujoints in that one wore out (shoulda used newer parts) and I swapped to Borgeson parts instead of buying and cutting two new shafts, details here:
Solid axle swap on 100 - https://forum.ih8mud.com/threads/solid-axle-swap-on-100.1220199/post-14299873. I used the 450024 shaft, and it had to be cut down quite a bit.