What timber to choose for window frames

Hi,

I'm right now shopping around for a suitable timber for the sliding windows that I plan to make this winter. I made a prototype of it some time back that worked out quite well.

Attachment 494488

This window is made of Baltic pine (the one Bunnings stocks) and I guess it would be sufficient. However I thought of a nice hardwood for my house. As I don't know a lot about the Australian species, I use mainly google to get some ideas and came up with Merbau, Jarrah or Karri. Ridgewoodtimber offered Kapur but I don't like the structure and those greenish areas that it apparently has.

The main question is, are these timbers suitable for windows (there is no direct rain getting to them) and what other timber could I use? Price is also important, because I need about a cubic metre timber for all the windows.

Cheers,
Andy