Electronic is safest.

http://www.ebay.com/itm/52mm-GlowShift-Tinted-Electronic-100-PSI-Fuel-Pressure-Gauge-Meter-Kit-w-Sensor-/351087007487?hash=item51be6a96ff&vxp=mtr...

Yep. What he said. You can still find plenty of old R12 hose sets around to take ends from. I'm not sure what you're doing but you could use this hose, cut off one end, and get an auto parts store...