I have been swirling this idea around in my head for an all wood deck that has a similar built in enclosure like the carbon fiber decks. In order for the board to be sleek I need a opening through the entire deck, but this of course would reduce the strength when weight is applied.
In order to compensate, an aluminum or carbon fiber stabilizer would be put on the bottom of the board around the opening. The top portion could be made from bamboo for extra strength. The extended enclosure is a separate section that is bolted on after the support and extends to the edges of the board for a sleek and seamless profile.
Here are some of my concept models:
Exploded Top Deck
Exploded Top Deck Close Up
Exploded Bottom Deck
Profile with Enclosure
Back w/ Wire & Button Holes