I can help you out here, Just go with Allianz no one else is cheaper from my run around and most wont offer insurance against it.
Also be aware that most providers are all under sun corp and aami meaning there not worth even considering with a car at this price point.
Here is my results in case you do want to ring around:
Allianz = $135 per month with a 2500 excess OUCH !
CGU = 589 per month with a 2000 excess
Suncorp ( AAMI/GIO/bingle/Shannons= wont insure except shannons who wanted $700 per month
Youi = wont insure
RACV ( Victoria) = $289 per month
BMW/Westpac are both via Allianz yet more expensive than going direct with them so don't bother.
So yeah in short go with Allianz.