Fitech EFI and custom gauges

[the idiocracy]

I am starting a new gauge panel and I was thinking about the mechanical vs. electrical route. Current dash setup is stock '67 so I only have a speedo, fuel (doesn't work with aftermarket fuel cell), generator and temp lights, not gauges and turn signal indicators.

Engine setup is original 250, with a turbo and Fitech EFI.

I am looking to run a 7 gauge dash and any help regarding signals for the gauges would be great.

Speedo - mechanical or GPS..either way...non issue.
Tach - electrical off the dist.
Fuel - I have to find a gauge the works with 0-90ohm sender or a means to convert the signal from sender to gauge.

Here's where I start to loose the plot...

Temp / Volts / Oil / Boost
Should I stay pure mechanical or should I tap into the FiTech harness?