Well, I think you might want to give us some more details, about what equipment that you already have. Do you have a multimeter, even a cheap one, that can read voltage and amperage? If so, you might want to use these gauges for some other specialized purpose, that would benefit from analog gauges. Those units are somewhat treasured and can make nice and useful projects. But, if you already have a multimeter, I think you would benefit from using the gauges for something else. Just my opinion and it certainly doesn't have to be yours.
Those gauges don't look like they are complete devices. Are they going to require additional circuitry?
Have you tested them, to see if they are operational? Look on YouTube, for tips on how to check them.
Your drawing shows a 500 watt PSU. This is an amazingly large power supply. 12v @ 41.67a and 5v @ 100a. Most basic power supplies are around 30v and 3a. Was this just some funny text, for the label, or a real desire?
I am not sure that I have an opinion about switched inputs. Maybe other people do.
I understand wanting to consolidate and compartmentalize your gear. There are lots of threads, on this particular subject. Consider a place that you could dedicate to your gear. This can be 1/2 of a closet. Install a cabinet in it that has a fold down desk. Add a folding chair. Some people use rolling tool chests. Keep it next to a desk. Like I said, read up on it. Instructables.com would surely have some good ideas.