Use at least a 6", for that much distance and head you may need to use two pumps with the second about halfway to the outlet point to get the volume you want. If you don't exceed 20 feet of suction head you're probably okay, would be best if there's any way possible to put the pump within about 5-10 feet of the pond surface. Hard pipe of some kind for most of the distance will be more efficient than discharge hose if you can swing it. A good pump rental outfit may have rental pipe also.
Another possibility is a big electric three phase submersible with a diesel generator, I have seen these used for moving large volumes.
In another lifetime I worked for a dirt company as a mechanic/truck driver. They were cleaning out a little pond, maybe thirty feet across, a few feet deep, wanted to muck it out and rock it back to fill it over. They hollered at me to load up a 4" pump and bring it out "that 4" will suck her dry in no time!". They ended up with two 6" pumps and a 5" rented, all pumping 24 hours a day with a tender at night to watch them and keep them fueled to stay ahead of the water. During the day running a 380 hoe, ten solo dump trucks hauling away muck, and six end spills hauling 4" rock for back fill! After a week or so they managed to put enough rock in to close it over, along with three "Wet wells" (said dry wells on the prints, lol) and a 24" ADS perf drain pipe running off the property. Point of the story: sometimes there's a lot more water there than you might think!