I went with in line tube. Good fit and reasonable price. They sell steel and stainless. I used the steel. The tubes are pre-bent and have a "shipping bend" in a straight section so they fit in a 6' box. I had no problem straightening the shipping bend on a concrete floor per instructions.

Aluminum is sometimes used sucessfully on home built systems but its toughness and resistance to alcohol have been questioned so I stay away from it for fuel line.