The leg extensions are available to make the conical fermenters easier to transfer your beer. They allow you to fit your keg or bottling bucket underneath the spigot. If you have counter space or a strong shelf to put the fermenter on, you may not need the leg extensions.
Another alternative is using CO2. Since the Fermenators have a pressure capable stainless lid, you can use CO2 to pump the beer up to six feet above the Fermenator.