http://www.scorptec.com.au/
http://www.msy.com.au/ - one of the cheapest in aus. but service is like shit sometimes. takes forever to get stuff as so many people go there.
I have bought hdds form them in the past (mainly cause im from interstate and we dont have a msy here). they still work so they seem alright i think.
In terms of cpu. I personally like AMD because they are cheaper (like 1/3rd of the price of intel for top models).
gpu I like ATI because I found that outputting to my tv ATI was sharper and brighter. My Nvidia card the output to the tv kept getting darker and darker.
for hdds it is really hard to say. it depends on luck what works.
I know here SAMSUNG are good. but i got one from vic and it failed. all my segates i bought here failed. Western digitals from vic worked for me haha.
dvd burner i found samsung and pioneer to best at burning and reading discs.
