FWIW, Sam Devlin's boats are well and truly sheathed in glass and epoxy. In fact, they look a great deal like fiberglass boats. How he manages to get that kind of finish and still make any money, I have no idea. I think he says "20+ years" because the technique is new enough that there are not that many wood-epoxy boats older than 20 years. The clock's still running; they may last 100 years or more, but we won't be around to find out.
If you're really worried about the boat's longevity and are totally averse to surprises down the road, build it traditionally out of the best wood you can find. It may not last any longer, but eveything that can go wrong has already been discovered over the past several hundred years, and you can replace one piece at a time. That's not what I'd do, but it's your call. There is, however, no evidence (yet) that a well-built and reasonably well-maintained wood-epoxy boat won't last a very long time.
[ 01-26-2003, 12:44 PM: Message edited by: Keith Wilson ]
"For a successful technology, reality must take precedence over public relations,
for nature cannot be fooled."