I think I am leaning towards going with a metal bed floor, what gauge metal, would be best, and opinions on metal vs wood? I've seen some nice metal floors and nice wood floors, I think metal would be less expensive. Any metal floor pics would help the decision making process. Originality is not a concern, this is going to be a hot rod/rat rod type of build.
Don

 

There's a couple different ways to do a metal floor, assuming you want a more original, ribbed look. A lot of guys have cut the floor out of a late model bed and used that. Years ago, I worked in a shop where we had a customer wanting a metal bed floor for his truck, and we found it easier and more cost effective to have a floor made at a local metal fab shop with the ribs bent into and formed to the correct size, rather than hacking up something used. It looked absolutely fabulous when it was done. Unless you're planning to haul rocks and trash with it, 16 gauge would be more than sufficient.

 

Definitely put ribs in if you go with 16 ga, oil canning and flexing will be very significant without unless you use a pc of plywood under the metal. I would use nothing less than 12 ga without ribs and without plywood

 

A 4x8 sheet of quarter inch diamond plate weighs about 360 pounds. Would be strong and with that weight the back end of the truck would would be stable - like a few sacks of cement to keep the rear of the truck from hoping and sliding in the rain/snow