I added oil pressure gauges to 2 of my boxsters in the same location. The gauge can be seen with both three and four spoke steering wheels. The hardest part is running a wire under the console to connect to the sensor on the engine.
In one case I used a cheap VDO clone gauge and sender from Amazon. The pressure sender for the gauge can be installed on the bank 2 head, keeping the idiot light sender on the bank 1 head.
On the other car I used a VDO gauge and the sender from a 996 which has both idiot light and gauge senders. The gauge is visible with both three and 4 spoke steering wheels.
Another possibility is an LED gauge something like this. The photo is a (very) temporary temperature gauge I installed while working out a wiring problem after an engine swap, I would think a place could be found to install it properly.
