making custom fuel tanks

I need to make a new tank for the fairlane and was wondeirng if there was any guides for this? I was going to make two sides and bend a sheet over them and weld solid. a veed bottom to collect fuel at the pickup and transfer the old sending unit to it. how thick should I go on this? will 18ga be enough? or should I got thicker? would it be fine to have a angle flange on the ends to bolt it up without straps?

On "Monster Garage" (you DO watch Monster Garage don't you?) a couple of weeks back, they did some fuel tank surgery and sent the re-worked tank out to have it lined in urethane. That would not only guarantee a leakproof tank, but also eliminate future rust. Something you might want to check into.
18ga should be fine, but instead of a V, take a look at using one of those pre-fabbed pickup sumps you can weld to the bottom of the tank. And don't forget to add a baffle or two.
I was thinking of having a inverted V on the inside as a baffle. it would have the top open and be at a low angle to horizontal (roughly 20 degrees or less) I got some of that eastwoods tank sealer from when I sealed the tank 2 years ago and was going ot use a similar product again (same stuff from JCWhitney for lots less) I thought about one of the premade sumps but they cost $50-60 and the whole tank isn't even going ot cost me that much.