I'm from South Australia. I used to shop with Peter at Complete Cycle on Cliff Avenue, South Coast cycles on Beach Road. Unfortunately Standish is closed now at Morphett Valve, that was good too. There's also Victor Harbor Cycles that's worth checking out if you're on the Fleurieu. Recently, online, I ordered from Anchor Bmx in Collingwood Vic, and I highly recommend them. They had the stock, fast postage, no fucking around. I'd stay away from the others personally lux, source strictly etc, only because most times I've ordered they've never had stock despite saying they did, so lengthy shipping times on back-ordered goods. Plus, the international sites don't quote the GST, they surprise you with an increased bill after you've placed an order. We also have a bmx sprocket manufacturer here in our state, and there's excellent wheel builders here, aswell.

Grips, I went overseas with - ODYSSEY BMX TOM DUGAN GRIPS (UK) $29.22 (EBAY) For a seat, try - https://www.goeasyonline.com.au/ (btw I have a new spare pivotal seat I'd like to sell, if you're interested, PM me and I'll do it cheap azf). Brake line - Try "Trade Products", Mount Martha, VIC, Australia for good quality stainless steel braid wire. Brake pads I'm not sure on because I usually file my pads and sand my rims and get years out of them. I know tektro make good pads, same as dia-compe but not sure where to get them locally. I think most bike stores would carry quality pads if you ask them. Hope that helps!