To recover a broken down car you can hire a sort of platform that has a winch to pull the car up the ramps. To move machinery, you need a loading platform not a lowering trailer....expensive and heavy. Furthermore... if you want to move machinery your problem does not start at the back of the trailer but at the side of the machine location...All in all I think that a cheap forklift and a conventional trailer would perhaps result in a more practical and widely available combination.