Do you have a lathe? If so you can easily make a bearing head for retrofiting or building your own stand. I turned the shaft for mine on my lathe. Used the indexing vise for my mill to drill the holes in the lock plate.
I've got a couple lathes and milling machines, welders, yada yada. I actually had to sell two lathes, surface grinder, metal shaper, Miller Dialarc HF, and a milling machine among other things to get my Cuda in the garage, I still have three lathes and two mills, though one is a little one. The build you described is what I am shooting for, just looking for a good starting point. The material I have on hand is too small. by the time you buy a bunch of 2-3" square tube and casters, you are at $100 so starting with a HF or other one is worth the time to modify it, if you start with a good base.
