I have my fuel cell installed and now want to run 1/2" fuel line all the way to front but don't know where to get steel line that long . Can copper be used ?
No you can't use copper, you can buy a 20 or 25 ft coil of aluminum line from Jegs. They also have AN fittings with hard line adapters that will make your connections without using a lot of braided hose. Try to stay away from the rubber hose.
Just because the rules allow it don't make it a good idea. Copper is a bit prone to metal fatigue, and it also has some rather unpleasant effects on gasoline as well if left in contact for long periods of time. There are a lot of sources for hard line; I'd probably get a coil of it from Summit, Jeg's, or McMaster-Carr.