To make it hands free you can have a flow control switch and a float at the tank, set the tank to fill when it is down to half and a second float switch (as you are surface level) to stop the pump when the pump is almost above the water. Or if you are petrol you could just go start it up (you would need a foot valve on the intake and pump below the water level as it would have little to no syphon till primed and would wear like a brake disk till the water is there.

Last with the tank you can have a float in a tube in the tank with a wire and red ball to show you how much water is in it ours was vertical initially but we had to go U shaped and show the water level on the outside of the tank when the wind kept bending the steel wire.

How would you power a 2hp pump as that is 1.5 KW and 2.6 Gallons an hour so tank size etc.

This gives you a starting point as for the pipe I would look at LDPE and a continuous run as there would be 35ish PSI in the pipe continuously. LDPE is sun stable so can just sit on the ground and can be rolled down the hill and wired in loops around trees to hold the weight of the water unless you want to dig and bury in a trench (without water in the pipe you will need to dig it in 1 to 2 feet and put in a gravel base for water to flow as it will float when the ground is waterlogged) I would leave it on the surface and loose some length in loops around trees (not too tight as you do not want to kink it).

Anyway that is my 2c and all the traps I can think of.