[PSIG]

The thing with gauges, is that they are just swinging needles with a voltage input to move them. Then they put a label on them to show increments of whatever you're reading. While not on everybody's can-do list, most any gauge can be re-faced to read whatever the sensor sends out. If you find a multi-function gauge (like Faria makes) that isn't right (ammeter and water temp or something), you can likely change it to what you need, if you're willing.

Else keep searching for what you need, and a quick search of "multifunction oil pressure ammeter" turned this up in the UK on eBay. The listing is over, but that's the idea, and who knows the size, senders, etc. Good luck!

 

[PSIG]

Volts and amps are not one better than the other. They are different information for different purposes. If only allowed one or the other, my first preference in automotive scenarios is ammeter, as it is much richer in diagnostic information, depending on wiring.