i dont know wehere you can buy parts @australia, but i would take a ROG ranger mobo/or a gene, i5 4xxxK processor (with a nicer cooler than intel stock and a 770er gtx with spezial cooler (not reverence) an 240gb ssd from samsung or crucial for system... case take what you like... but favorite of me are fractal design ARC cases in the lowend segment...
😉 looks heavy and the quality is ok
Greez JT