1) Cant talk about aus, i'm usa.
2) The build looks good.
3) I am unfamiliar with Aywun, but in general, the only case/psu combo I would trust is Antec. Do more research there, and DON'T buy a cheap psu.
Your parts do not need much cooling; any case should do the job, even a cheap one.
4) The 5570 needs only a 400w psu: http://www.amd.com/us/products/desktop/graphics/ati-rad...
5) The llano is strong on integrated graphics and weak on cpu. Considering that you already have a graphics card, stick with your sandy build.
6) Take the time to download and read, cover to cover both the case and motherboard manuals. They will answer many questions you might have about your first build