So the PLA Z rod/motor couplers didn't work quite right. The PLA is a bit brittle and as I tightened the screws, I heard a bunch of cracking. It seemed to hold for a bit, but then later the couplers just slid off of the Z motor shafts. You can see the cracking in the couplers in the following pics.
I milled out new couplers from some aluminium stock I had on hand. I drilled through at 5mm and then drilled half way through at 8mm. Then I cross drilled some 3mm holes for set screws and tapped them for m4 threads. You can see the couplers on the machine in the following pics
And I've gotten a method for hot bed mount done. I'm using plywood and have the heat bed attached to one sheet and have made it so I can detach the heat bed easily if I need to. The attachment method allows for easy adjustment to level the bed to the nozzle. You can see it in the following pics.
I still need to find connectors with sufficient ratings to connect the bed to the electronics. Also need to decide on how to attach to the electronics. And then I need to attach the endstops so it can auto home and stop the +Z motion before the belts hit the frame. I hope to have things done and printing any day now.