Read up on Loake's sizes and last types. Try on Loake's at DJs, paying attention to fit and the name of the last. Once you have a last that fits, you can go shopping online eg Herring, Pediwear, Shoehealers etc.
Go to Cloakroom. Try on the Carminas. Buy them at $700 per pop, or go online and order direct.
I am not sure whether there is a Herringbone shop in Brisbane. They have C & Js.
Visit Meermin website. Measure your foot for width and length, and trace out foot outline on A4 paper and mark measurements. Send over to Jose of Meermin by email to get help on sizing and lasts. If you stuff up, Meermin will usually take it back, but remember that it costs AUD$90 to return shoes to Majorca.