mo,
Get some good heart cypress. That's what I would use.
Something that fascinates me is the superior durability of riven wood vs sawn wood. I saw this demonstrated by a photograph in a Roy Underhill book. They took a riven piece of red oak and a sawn piece (same section and length) and submerged one end in water and someone blew on the other end, like making bubbles in your chocolate milk. The sawn piece had air bubbles escaping all along its length. The riven piece only had bubbles coming out the end -- like a straw.
Goes to show that water/air has a harder time penetrating the cell walls than the places where a saw severs the grain.
Gabel
