You could use POR 15, but it will need some sort of topcoat. They do make topcoats that are made for use with the POR 15, and you could also use regular paint if you topcoat with their Tie Coat primer. I did my bedsides with that.
I will also add that unless you plan to either install a tonneau cover or some sort of bedmat to cover the wood, you'll be dissapointed with Pelucid. i did my wood with it, and while it looked great, the finish just doesn't hold up to UV very well. I'm currently in the process of stripping my wood for refinishing as the Pelucid started to peel from UV degradation.
