Ok, on the temp gauges...do you have harnesses yet? They use pull-down resistors, and the sensor you need depends on the harness you have. I have three oil temp sensors available for the "old" harness about 5+ years ago, but they're now using the same harness/sensor for both water and oil.

Oil pressure you can use an Autometer sensor and harness, as it does not use pull-down. I've got the formula for that.

Fuel pressure is prob the same sensor as oil pressure.

What do you have, and what do you want to buy?