Found the Western Digital 160gb Passport Drive (search SY160CASEK ) for $109.00 including the case.
The local Officeworks store price matched the business direct price and although the guy initially said that he had to add the nominal handling charge, he still ended up doing it for $109.00 with the case!
I thought this was a pretty good deal on this model considering the prices available from other stores and save on the handling charges.
In store retail price was $117.00 and case was approx $19.95.
Hope others find this useful!
edit: Also noticed that auspost's latest catalog lists the 160gb WD hdd for $109.00, albeit the old passport version instead of the passport essentials model.
Officeworks have a 160gb Seagate for $99