Motorcycle rental in Malbourne area (advise needed)

[SikorP]

I`m planning a trip around South-East Australia, starting and ending in Melbourne (19.10-8.11) and looking for a motorcycle. I would need a travel enduro class bike for me and my girlfriend as a pillion. I talked to several rentals but its quite tough to find something reasonable, i.e.
1. Biketours -> have for me only BMW1150 but they don`t allow to go off tarmac
2. Aussierider -> terrible expensive travel enduro bikes, no info on the insurance cover
3. Garnersmotorcycyles -> I almost decided to take Yamacha ST 1200 , but the insurance excess is $5000 and there is no theft cover on any of their motorcycles.

None of those have cheaper bikes such as V-strom, Transalp, etc.

Can anybody elaborate a bit on the motorcycle insurance in a Australia ? Is such high excess and no theft protection a common practice ? I`m really confused and stuck in my search for a bike

I went also through bikesales www site but there is not so much reasonable offers for me in Melbourne area.

I would also accept a bike swap - KTM 990 Adv available in Warsaw Poland.

Can anyone help ?