You might want to find a fab shop to do it. Just make a sketch of what you want and bring it to a welding shop. Just a tank with fittings welded in, and a gas bung. Throw a couple baffles in there and your set. Something like that should only take a couple days to make. You take it to any kind of marine shop and your paying big bucks. Hell, I'll bet you welder could do it in no time and give you a great price. If I do it, I'm making it out of stainless.
