Yeah,
Shannons is the main one and also our main sponsor. I have both my Eureka and my daily driver (V6 Camry) insured with then, and from memory it's less then $800 for the both of them, comprehensive and includes 1 free windscreen replacement (for both vehicles) every 12 months. Mind you, they're not perfect. A mate at work is also with Shannons, and he had to replace the windscreen on his daily driver. Lets just say it took a lot of effort to get them to cover the windscreen cost.
There used to be several others around, but they seem to have merged into one,
Lumley Special Vehicles. One of the other companies that merged into Lumley was Vigil. I just spent a bit of time looking for their site, and you get directed to Lumley. You also get a lot of links to various forums (Walkenshaw to Lexus forums, so a varying range), that say Vigil used to be fantastic, until around 2007, when the merger happened and they became "less than good". Unique Car Insurance, Torque (wasn't that a bike specialist?) Prestige Car Insurance, along with Vigil formed Lumley.