hey angelic,
i am in a similar situation - my bf has been offered a job in hk and i am going along and hoping to get work too.
re the working holiday visa (as opposed to a work permit) you DONT need to have a job before applying, you just need to have a certain amount of HK$ (i think it was HK$14000 for a kiwi, will need to check oz requirements) and its only for a year. mine was approved in 4 weeks.
all the stuff i read before i made my decision said you cant work on a dependent visa or a tourist visa, so if you want to work a working holiday isnt a bad idea

unless you can get sponsored and get a work permit?
just a note about the working holiday, you can only work for the same employer for a max of 3 months and you are only meant to work for 6/12mths.
sarah