Sheetmetal floor thickness?
 

I am building a 74 Javelin with a complete perimeter frame. The floor is going to be built around the frame and cage.
What thickness sheetmetal is typically used for the flooring, specifically in the seating areas?

Not sure what everybody uses, ive used 16g ans 18g mild steel, but tie the seat mount into the cage.

That was the direction I was aiming. Seats will be incorporated into the cage. I want to run as light gauge sheet metal as I can without oil canning. I am going to bead roll where necessary. Thanks.

I just did floors on mine and I used 18 gauge. I haven't cut the crossmembers yet but, with the tunnel, it is really solid. I had lots of oil canning after the bead rolling but, once it was welded in, it went away.