\ I plan on getting shut off valves so I can regulate the flow from the main pipe,

Maybe i can just get a standard PVC and drill holes to stick the 1/4 tubes into the 1" PVC. Then run like 3" of line, then attatch the valve, then a little more line. The valves will let me adjust the flow coming from the main pipe.

I saw bluebear describing something like this.

Would that 500 GPH pump feed 72 drippers, just so I would have better coverage?