Please advice if it is worth looking at buying some Hi-fi gear(amplifier and speakers), detalis like where and what to buy would be highly appreciated.
There is a shop called Clef Hifi in South Melbourne that is worth checking out. They might have some good gear on specials. You could find some really good deals on Krix from that place.
Also, JB Hi-Fi is a chain of shops dealing in music - huge collection of CDs, Blu-rays, LPs & also gadgets including amps, speakers etc. For amps, speakers etc, go to their huge shop on Lonsdale Street (there is another entrance via Elizabeth Street).
EDIT: Better way to buy is via eBay auctions. Look for deals that end late night Melb time. Them Aussies don't stay awake late for anything except partying. I have bought lot of stuff for my car using this route.