Many have used a late 60s/early 70s Mustang tank, since they are easy to purchase.
You have to have someone move the filler hole from the center to the corner. A radiator shop should be able to do it easily.
The 1965 Mustang tank is about the same physical size, but holds a few more gallons.
Later Mustang tanks hold more gas, and are the same length and width, but they get taller each year. This means you have to get some longer straps to hold it up.