Hi Brad
I'm a avionics lame so generally I just throw 'black box' faults at the Bench Techs. Being in remote locations I send them to shops around the country.
Even your average Avionics LAME find Bench Techs a bit weird but we are always in need of good ones. I find workshop people are a breed unto themselves.
It's better to turn up to the Avionics shops and introduce yourself. Some of the GA ones are Complete Avionics on gold coast ,Quality Avionics at Archer field and Range Avionics in Toowoomba. I think they all do bench repairs
Sometimes the military advertise for people at Amberley and Oakey. Rockwell Collins was also advertising in the Brisbane area. Mainly these are for fully qualified people.
Advice would be flexible and be willing to move, plenty of repair shops around the country. If Electronics are your thing then Radio repairs should be where your headed. Otherwise you can specialise in instruments.