Dad6timz,
Congratulations, I envy you, I finally have a place to work on mine. I have gathered plenty of parts and trucks, and I am just about to begin the rebuilding and restoration process.
What about a flatbed, that should be pretty simple? If you are determined to build a wooden box, I have seen one or two in the gallery that have a wood box with the original fenders. Those looked pretty cool, unfortunately I don't remember the year or owner, you'll just have to browse until you find it. As far as dimensions go, that is all available also. You need to check the links, I know it's all there, as I have seen it. You may try and check "Brads 41 thru 46" or something like that. He had a lot of good information posted.
Good Luck, and keep us informed on what you decide.
John