dude a trail truck is the ideal application of veggie. Just need a few gallons per trip (unlike everyday driving where you would have to track down several gallons a week), and instead of smelling like butthole like most diesels, your exhaust smells like french fries!
I think the ammo cans I have are as big as they get. Not cheap either, like $30 a piece. I think they're 30mm or something weird?