As I now understand it, you have 40' of standing water sitting at the bottom of a 100' well, with power lines overhead. Current pump inlet 80' down.
Making a committment to a sucker pump is somewhat expensive, even if half the system is scrounged, so I don't suggest running out and spending any money without first studying the entire cost of a comprehensive plan.
If you install a sucker pump, the top can be cycled by a rocking beam. If an adjustable counter-weight is mounted on the other side of beam that is equal to the loaded water side, the beam can be cycled with very little effort.
At this point, the beam can be cycled by a rod-and-crankshaft turned by wind or a DC motor. My first choice for a rocking beam support would be placing it at the top of two side-by-side A-frames. Because of the overhead power lines, the beam could have a "V" brace mounted to its underside betwen the a-frames. If the rod was attached to the lower tip of the V-Brace, it would allow a horizontal rod to cycle near the ground.
I worked at the Burbank landfill. Its an older "moist" landfill, and trash decay produced significant methane. The city installed vertical wells to draw out the smelly swamp gas and burn it off (flaring). Someone got a federal grant to install V-16 locomotive diesel generators with sparking added to make some electricity from this waste.
Percolating ground water filled the bottoms of the wells and restricted drawing up the now-desireable gas. Sucker pumps were installed (200+ feet deep) so via a cycling cable (fiberglas) a column of water was lifted to an aboveground sideways pipe "T", where the water flowed horizontal to a storage tank (don't ask how it smelled!).
On that application a single-acting air cylinder pulled the cable up about six inches. When the air-piston reached the top (top was open, air pressure was under the piston on the pulling rod end) an exhaust valve was tripped, and the air-piston fell from the weight of the fiberglas rod and water-piston. The bottom exhaust was snubbed to soften the landing, triggering the air lifting supply again.
I got them to add oilers to the air-supply lines, so the air piston seals lasted much longer. The trashy water ate up the water piston seals, so when a well slowed production (~once a month, running 24/7), it was scheduled for me to pull the water piston, and swap it with an identical piston with new seals.
Another idea...I don't know if this would work for you, but I have seen systems with several centrifugal pumps stacked, meaning that the outlet of the lower one feeds the inlet of the next one up. This is how the local city water, and the submarine I was on did it. Might require 3 pumps or more to lift 80 feet, might not be worth it, even if it does work.
Just some ideas to kick around...
