[SS Engine Guy]

The larger the line diameter, the more instant the correct pressure reading. I would suggest braided line with correct fittings even with the extra room needed and extra cost. A correct pressure reading can sometimes help diagnose problems and also monitor fuel pump condition. Remember also that volume is really important also on a carb motor. A clear plastic gallon jug measured to be an exact gallon is always at my shop and in the trailer. My opinion, regardless of the et, is pump a gallon after the regulator, in 20 seconds.
If FI I would take pressure directly off the fuel rail or log. Just remember that you need decent sized line to give instantaneous pressure readings whether by guage or data logger.