You get the sensors out of a 1980s Cabriolet convertible that had the gauges, used or new, that's what they came from.
The oil pressure gauge is on the head. It has two prongs, one for the gauge, one for your stock idiot light. And there is an oil temperature gauge on the filter flange. You can also just mount some aftermarket gauges in the holes, like an EGT gauge if you want.