Suggested wood choice for building a porch screen door ?

We have a screened porch that a previous owner had built. The structure and roof were done well but their choice for the screen door was a cheapo PVC thing with plastic spring hinges that can be found at the orange and blue big box stores. We want to replace this door with a screen door hung from barn door hardware so that we have more usable floor space inside the porch or outside on the deck. I can't find any place that stocks a door wide enough for this, so I'm going to build one. My problem at this point is figuring out which wood to use (that I can get).

It's going to be painted. I figured douglas fir would be a good choice, but I can't find anyone around that sells it (central Virginia). I need a wood that will hold up in hot sun, rain, humidity, and occaisional snow. Will clear pine hold up if primed and painted? Any other suggestions suited for outdoors that will sand and take paint easily?

Being hung as a barn door, I don't expect to worry about it sagging. I figure I will just use pocket hole joinery, plug the holes, sand, and paint. I'll also be installing a doggie door in a lower panel.