With hydraulics, you can get absolutely any force with absolutely any power input. You can hand-crank 40kN with hydraulics. In fact, I'm pretty sure you could find a hydraulic car lift that does just that.
Now, if you have a force, say these 40kN, and the time in which you want to raise the load a certain distance, you can get power. Say you want to raise 40kN load 1 foot in 1 minute. That works out to roughly 200W. Factor in loses, both mechanical and electrical, and you are probably looking for a 300-400W motor. At 12V, that works out to something in the 25-35 amp range. You should be able to draw that from a car battery.