Have you tried Just Car Insurance yet? They are a specialist for modified cars and people with shitty records. They will insure ANY modification as long as it is legal. They offer Third Party, Fire & Theft Third Party and Comprehensive cover but they can be a bit expensive at times.
Give them a call on 13 13 26.
Shannons are a good option if that is the premium. I don't know if Vigil can help with cover...
Other than that i can't think of anyone who will do it, you can try a broker (Insurance Australia Broking) but sit down before they tell you the premium.