I would be looking at Option numbers 2 or 3 first before changing the clutchfan.
If you have no idea how old the radiator is, and it looks a little tired, chances are it's due for a cleanout. Take it to a decent radiator place and have them do a proper cleanout and flush on it, none of this jam a hose through it and hope its ok
Otherwise, its possible you have a sticky thermostat, which could explain why its only overheating every now and then. Occasionally frees up and runs fine, but sticks most of the time...
Possibly then look at clutch fan...
Does it only overheat when stationary or at speeds below say 60, once on the highway it cools down? Suspect clutch fans, and blocked radiators seem to show similiar symptoms, so can be hard to judge.