what size/gauge metal to do cab floor, firewall, etc.....

as the title says i am trying to see what is most recommended for redoing the cab floor, firewall, and the bed/ notch cover area....

I BELEIVE IT T BE 16 GAUGE. BUT I KNOW SOMEONE WILL CORRECT ME IF I AM WRONG

ok thanks...anyone....i just want to get most commonly used or best recommended for a custom floor bd....and whatknot..

there's some design that goes into how thick your floor is. if you run a plain flat floor thicker is better, but i bet the stock floor is like 20g. it has tons of strength from the beads and brakes in the pans. that's something to think about. if your not going to do any type of bead or anything go with thicker (and heavier) gauge. sure 16 will do ya fine. i personally would do 18g with some beads n shape.
for your bed - you can get away with thinner sheet here too, because you'll likely not be hauling anything nearly like what the stock bed was made for hauling, and i assume you'll make a skeleton out of like 3/4" square for the metal to sit on.

yeah i have a good layout just need to get the sheets and get to fabbing thanks speedster for the info....i see what you mean about the breaks, overlaps, beads etc, good point thanks again.......