Here's a link to some $125 pressure transducers that should work well with data logging systems, or stand alone diagnostic, gauge, or emergency boost control uses with an alky. kit for the DIY'er of course.
General Industrial Pressure Transducers 0.50%-Industrial Automation
Using a 1% 250 ohm resistor accross the 20ma output would give you 0-5 volts for your typical logger.
8-30 Volts excitation which would work fine with auto. voltages.
0-300 psi. model would work great for larger pumps.