So I've got the hardware designed, and actually had to go back and make a few changes as I was poking around in Blender and realized some of my parts were, for lack of a better term, in each other. I think "intersecting" is the term kids these days use.

After re-engineering some of the brace designs to make them more sturdy, and also exist in a mere 3 Euclidean planes, I've (hopefully) finished the hardware and now I'm just waiting on it to actually get shipped out here. That's something I have no control over; if I had the money I'd just fly across the country, pick up a few boxes, and fly back, but that's not really an option for me right now.

Once things get shipped over to the western side of the country I'll be able to actually start constructing with them, and hopefully that part will go very quickly. Cable routing will be a pinch, even though I don't have it in any of the renders, but that's more due to the fact that my modeling software is very old and doesn't have good soft-body modelling features, and I'm nowhere near good enough to set it up in Blender.

Tl;dr — had to make some revisions to let the arm exist properly in only 3 dimensions, and waiting for parts to arrive so I can finally begin working on it.