No specific recommendation (it would be improper of me to do so), but any of the major general insurers in Australia should be able to offer you some form of cover:
Flood is covered by *some* insurers, subject to conditions. You should check your policy statement.
Just as an aside - The vast majority of home and contents policies include a Public Liability (PL) cover component.
IMHO PL insurance is vital for a landlord and I, personally, would not recommend anything less than $10 million cover per property (this sounds like alot, but it is not). The buildings insurance I take out (with one of the abovementioned insurers) includes a $10 million PL component as a part of the base premium.
PL insurance has been discussed a few times on the forum, such as in this thread.
I use Elders Insurance at spring hill, they are actually insurance agents/brokers and have been able to help me with anything from car to bodycorporate, landlords etc. Any good insurance broker should be able to help.