I bought relatively small nozzles to start with. My pump will flow 2.5 gpm and with the bypass closed will put out 60 psi as set up. The chart that came with my nozzles recommended 30 psi, IIRC at 7 mph they put down a little over 12 gallons per acre. I sprayed the yard with Crossbow with it set up a recommended and will see how it kills and adjust from there. These nozzles will work from 10-40 psi, so adjusting the pressure and speed I think I can make it work for what I need.
So far the only change if I were doing it again would be to lay the ss T down instead of up and making the 1/2" feed line longer, this way the tailgate would open. I have another T and am thinking about changing it out.