911 Carrera twin turbo.Where to place the sensor for 2 turbos

[MrShades]

I am thinking of installing a boost gauge(or place it on the tacho)from InYourFaceGauges.
Where do i place the censors for having the most correct boost reading on my 1985 911 Carrera twin turbo?
Or do i need to have one for each turbo? Can i place the censors on the intake? The intercooler?

[sjf911]

Are you planning a mechanical or electric boost gauge? Boost only or vacuum/boost? I run a mechanical boost/vacuum gauge in the dash clock hole off of my brake booster before the check-valve but I also log off of the throttle body vacuum port with my MAP sensor. My H2O/methanol injection controller also provides a digital boost gauge and comes off of the brake circuit.

[MrShades]

I am planning on electric boost gauge. Thinking of something like thisPLX gauge:
YouTube - Custom Porsche C2turbo PLX gauge