Proper Large Scale Drip System Setup

[surfingrob]

How to setup a drip system I wonder? I tried just using home depot stuff with a sump pump but it doesn't seem to be enough pressure. I'm trying to feed 50 plants with 2 drippers to each plant, 4GPH or so would be fine.

Is there a calculator or something to figure PSI and GPH of the pump and the diameter of the piping to use?

Please help, trying to setup a drip system so I can lay off the hand watering.