Well funny that.. you have the OEM 18s and want the 19s, I have the OEM 19s and want the 18s, only problem is, I dont want to sell my 19s too bad ur in Melbourne too as I can't find any OEM 18s anwhere either.
Best thing about using OEM wheels is that it sits perfectly on the hubring without requiring the use of a plastic centric hubring locator