To clarify, it's difficult to appreciate just how HOT 620-700degF really is (lead working temp). Most people are used to dealing with hot food, but most food/stovetop/oven use never gets much above boiling, a mere 212degF.
Liquid liquifies at ~621F. You can get there on a wood fire, but it's a whole lot more difficult that boiling water! You'd really want a bellows and a boy to pump it.
If you already have a propane turkey fryer, you can start with that and steel pot with a ladle, but it's not nearly as convenient as a bottom pour electric pot. Don't make the aluminum pot mistake.