Re: Are these components all compatible?
Nah nah sorry man. Im in Australia too. What area are you in, ill look for a local shop that has cheap 4850's.
Its just that most of the time you get an older card (remember a 9800GT is just a renamed 8800GT) that has 1GB, its usually slower than the cheaper 512mb model.
EDIT: Here, this place has 4850's for around $190 (generic though)
msy.com.au - Their site looks like crap but ive been to one of their numerous shops and they are pretty good.