I would look up "known problems" on what you have and get gauges for what might be a problem for you someday. For what I have...a fuel pressure, oil and trans temps are good indicators of what is going to fall apart next. My rear axle is a Dana 70 so I also installed a temp gauge for rear end. Matter of fact I have toggle switch to monitor temp's on trans and diff using same gauge. Have you checked out "scan gauge"? Again depends on what might fall apart on your set up. At same time I don't think you need to have gauges that are watching other gauges.
(After I had trailer plug loose connection one time, I have been thinking about a small LED light up to dash via charge line, letting me know if elec is still connected).
2003 Majestic 23P... Northwest travel machine
2013 Arctic Fox 25W... Wife "doll house" for longer snowbird trips
2001 "The Mighty Dodge"... tow vehicle for "doll house"