Must have nothing else to do?
My set of guages on the shelf for the last four years or so.
I would suggest the best spot for boost is simply tee off the MAP sensor line (just be aware of the usual blockages that occur at the manifold).
I was planning a new tap at the top of the manifold, just after the "throttle" flap.
I was planning to put a T-piece at the Oil pressure switch. This is obviously where the engineers decided was the best spot.
I don't like the idea of comprising the filter mounting.
For the illumination, either tap near the fuse panel or tap into the 12V socket light wire.