Things to consider when selecting wood for a truck bed.
1. How will you use it?
2. Will it be stored inside or outside?
3. Originally they were painted black. Do you want a painted bed?
For my truck, which I leave outside, and use for hauling building materials, I decided to use purple heart with an oil finish. It has been over 1 year now, and I'm still very happy with my bed. If you click on my 48 link below you can see photos.
If I wanted to paint the bed, I would have made it from doug fir and saved a couple hundred dollars.
Chris