Hi @manninkin33,
Thank you for your question and welcome to the Bunnings Workshop community.
The best timber to use is dependent on the specifics of the project. If you could take some measurements and upload some photos, our helpful members will be able to offer more specific advice. Let me know if you need any assistance uploading photos.
While dependent on the project specifics, the type of timber that is best for this job is LOSP Pine. This is a dressed Pine product, treated for external use and pre-primed for painting. It comes in a variety of sizes and profiles for a number of external applications.
Once we have some specifics, I'll be happy to answer any further questions that you may have.
Jacob
