That fuel line is stronger than you think once you get all the bracing done it is very strong hollow or not. I can set on my Beretta chassis and it dont move/flex at all and i weight around 180LBS. as far as the sheetmetal you need to look around any home improvement store will have alot of different gauges. I used heating/air ducking sheetmetal it's cheap and easy to work with. a good pair of sisors will cut it with no problems. i got my sisors at Harbour freight,,, if theres one around there...stoneyberk
www.quarterscaleberetta.com