I love the look of Rob Englishes GMC Huckster. If I didn't have bedsides, that's exactly what I would build.
One thing to keep in mind however, is that pressure treated wood eats steel. That's why deck screws are so expensive, they have a coating to protect the steel screw. I built wood frame steel buildings (pole barns) for a couple years, and anywhere we used pressure treated wood, we used stainless steel screws.
I guess my point is, you might want to line the edge of the fender where it meets the wood with a strip of rubber or something
