Gilly is pretty well right marksman,that crush proof pipe in the picture is way to small,start with the same size pipe as the outlet on the leaf catcher.it depends on what you are chasing -water pressure,water volume or both ,i think your biggest hurdle will be the height of the sluicebanker,you will have to have the input on the sluicebanker at least the same height or lower to get the same flow out as into the pipe.
You may have to re think the spray bar ,change it from pressure to volume ,so you are not restricting the flow to much.
A example of what i mean-lets say in my sweet potato washer with the brushes in it ,if i ran a pump at say 5,000litres a minute at 30 psi the spuds would come out of the wash with mud on them.
The pump that i ran moved 22,000 litres a minute at about 10 psi, the spuds came out clean, it was water volume that we had to have to clean the spuds not water pressure
Trying to make it a pressure wash can cause a lot of problems if you do not cut the different sized pipes at the right length it buggers all water volume and pressure,i have installed a lot of under ground irrigation pipe, and if we did not follow the blue prints the system would not work.
With my experience with water flow, i would err to the volume side of things.
It is all trial and error and remember the longer the pipe less water
just my thoughts marksman :Y: