Haven't lived in Sydney for a while but I used to go here a fair bit: - Cyclery Northside - however as I have a lot of friends and family in Newie I found that it was often cheaper to get things when I was home. They don't seem to have any clothes on their site, just the bikes, they do have a fair few clothes in store.
Sadly not been on a bike for about 5 years, there was one day where I couldn't resist it and took it out but only about 30ks, had a few accidents - broken collar bone and some ribs, that wasn't too bad for cycling, but then got 2 torn (both right) and 2 detached (1L, 1R) ankle tendons and on top of all that carpal tunnel which makes cycling even less fun!
you can always try websites such as:
Torpedo7 | Outdoor Gear Store | Extreme Sports Australia Shop Online
Cycling: Buy Bikes & Parts in Australia | Cheap Bicycle Gear Online | Torpedo7
UK have a fair bit for cold cycling:
Chain Reaction Cycles:
*Chain Reaction Cycles | MTB | Road | TRI | Run
Wiggle | Cycle | Run | Swim | Tri-Sports & Bike Shop