I need to replace a gate and want something smarter than a treated
softwood one so am looking for advice on what timber to use. I found a
picture of exactly the sort of thing that I had in mind he
http://www.the-green-oak.co.uk/pic_317.jpg
This is obviously oak, but would I use green or seasoned oak to make
something like this?
I've never made anything that would be exposed to the weather like this
- presumably I need to worry more about the expansion and contraction of
the wood. If I used 6" wide seasoned planks for the front face of the
gate is it going to expand and deform/split when it gets wet?.
Any advice greatly received or ideas of a book that might help me with this.

many thanks, John