Dave,
The problem I have with any of the solutions that involve surface mounting on the dash or in front of the gauge cluster is the wiring being exposed and looking very aftermarket. I have the single gauge pod, and I will try to take a pic for you from my driving position and head position because I can tell you I have lost no vision. The angle of the pod keeps the gauge and pod in the same line of sight as the A pillar itself which you can't see through anyways.
I don't know if this would be the case with additional gauges mounted higher on the pillar though. I still feel the A pillar is the best location to give you full OEM gauge cluster viewing and a gauge right in your line of sight when on the track. By the way your positioning of an oil pressure gauge had me thinking, does this car have an OEM low oil pressure light? Has anyone seen it flash during hard cornering?