Nozzles with twice the flowrate will give you less control over the mist and are likely to produce larger droplets. You have the option of using a longer pulse with lower flowrate nozzles.
Running at 70psi / 80psi gives you 2 gals from a 19gal tank. 60psi / 80psi will be 4gal and 80psi / 100psi will be 3.3 gal. You should set the air precharge 2psi below the pump cut-in so the tank never quite runs out of water before the pump fires up.
You may struggle to find a pressure switch that can adjust down far enough to give you a 10psi differential, the minimum is usually around 20psi.
Running at 70psi / 80psi gives you 2 gals from a 19gal tank. 60psi / 80psi will be 4gal and 80psi / 100psi will be 3.3 gal. You should set the air precharge 2psi below the pump cut-in so the tank never quite runs out of water before the pump fires up.
You may struggle to find a pressure switch that can adjust down far enough to give you a 10psi differential, the minimum is usually around 20psi.