I had to learn alot about pumps, head and GPM for a simlar application. I called these guys and were unbelievably helpful (Pumpbiz.com) I am not a rep or tied to them in any way.
They recommended the following 4.7hp high-pressure unit for my application. This is not a trash pump, so filtering is important. It's rated for 110gpm and up to 167 feet of dynamic head. I think we calculated my application right at 100ft of dynamic head. Gravity is a bear.
https://pumpbiz.com/high-pressure-water-fire-pump-2-inch-honda-serh-50bThe creek bottom to the top of the hill is 76 vertical feet (thank you google earth) and total run is 590 feet (430' is uphill). I am running 40 feet of 2" suction hose and my pump is 5 feet above water level. The first 50' of my discharge is 2" lay-flat discharge line connected to 500' of 2" schedule 40 I trenched through the woods.
It works like a charm, minus the tiny 1 gallon fuel tank. Like you, I wish I could get that 200-500gpm but a giant pump was out of the question because the creek flow rate/ reservoir is too small.
