I personally ordered mine from Retro Access (US), but Retro Gaming Cables (UK) makes them too. I'm sure there are more sellers people here will chime in about.
I'm not sure I understand your concern with a CRT. I have mine connected with a meanwell PSU (from that thread), and I've connected it to a PVM and two different BVMs without issue. It doesn't have to be a PSU taken from the inside of an actual arcade cabinet. Just needs to be able to provide 12v and 5v to the HAS to properly power it and the arcade board connected. And a few older boards might require -5v as well.