I need to construct a simple(ish) high voltage circuit charging / discharging circuit, and a harness for connection. I need some help with parts and assembly. Here is a basic diagram:

https://i.imgur.com/BMHwN28.png


Questions / concerns:

1) I have a spare PC ATX power supply that I can use for 12v. My voltmeter has an operating range of 9 - 12V DC, will this be okay or do I need to step it down?


2) I need connectors with covers for safe HV connection. This is labeled “battery harness connection” in the diagram and should be something like this: https://i.imgur.com/l9IGAdI.png


3) fuses & fuse holders: would Mouser #530-3AG1-R and Mouser #441-R364-GR be appropriate?


Thank you for any assistance

 

addendum in order to accomplish this:

4) I believe I just need the relay and a Zener diode. Would Mouser #512-1N4742A and #653-G5V-1-T90-DC12 be appropriate?