Good news and bad news: The cypress will last forever, however it must be from a tree that is 70 or more years old. Now I don't know where you will get cypress wood that is that old or if you can prove it is that old. Perhaps some specialty wood dealer would be able to steer you in that direction. It is a good idea to find something you won't have to "do over" while you're alive. I had thought about using teak.
