Here's the deal. With wooden houses, you have to worry about termites and rot. You could get pretreated wood--the problem with that is that the wood is usually treated with arsenic (there are safer ones out there too). There are natural types of wood with are resistant to rot and termites like redwood, cypress, and surprise, surprise, cedar--these tend to be more expensive however. In addition, the soil around the foundation has to be treated for termites so they won't set up camp the moment they see a weakness in the wood. This doesn't address that you have to find a good construction company out here that has knowledge in working with it--almost all out here use concrete.
Now, if you don't want prefab, you can try adobe. It is simply a mixture of clay, water, sand and stray, hay, or even manure. It is easy to maintain, really good insulator and it is already being used in this part of the world. :)
http://en.wikipedia.org/wiki/Adobe
Mind you, I prefer a wooden house too, at least from the inside. The concrete and bricks houses here feel so sterile.