Mex,
Back when I worked a more or less regular job, I did a lot of computer maintenance. One company had many power supply failures. I found that they had a local builder make up the boxes and he was using a POS power supply. (Maybe because he also maintained them, so he got to charge at least twice.) When he was unavailable, they came to me. I put in three power supplies that were real commercial grade devices. When these boxes got left out of the fail/replace cycle. Questions were asked.
If I were in your position, I would search up power supplies with a very long published life (TBF).
I think you also might consider splitting the system so that you can't loose the entire system with a single point failure.
In ATX form factor, I can tell you reliable supplies, but for your installation, I can't be much help.
Matt
