I think it all depends how historically accurate you want to be.
Personally I prefer the grain of oak, but that's just my opinion.

The original pine bedwood lasted many many years,bearing in mind they saw far more use than most of our trucks today will ever see.
It's your choice.

1950 Chevy Advance Design 3100 in Scotland
In the Stovebolt Gallery
More pix on Flickr.
I've definately got this truck thing in my blood ... my DNA sequence has torque settings
"Of all the small nations of this earth,perhaps only the ancient Greeks surpass the Scots in their contribution to mankind" Winston Churchill.