CIA or any manufacturer might be interested in making production units that will cater to a market. The issue with the idea of making an improved PS for the Mac Mini in order to address sound quality improvements will fall into a really small niche category.
If you are serious about it, then there might be other alternatives that will either cost you $$$$ or serious DIYing. One off specialty PS will not be affordable in any sense.
One of the most talented PS designers/engineers is Peter Daniels of AudioSector fame. Maybe you can Email him, I got a nicely made outboard PS for my 47 Labs Shigaraki from him. Nevertheless, it was not how I can say affordable, and he will need to see the PS the Mini is using, unless he is extremely familiar to it. I have a MacMini and I can say that its powersocket might not be the most common, which also call into attention that if the PS designer cannot get a socket and a plug in part, then perhaps it might mean physically hacking into the Mini to power it.
Much food for thought.
