lol goodluck! If your under 25 its near impossible to get insurance (in WA atleast) from any company other than JustCar for skylines. JustCar will probably offer a ridiculous excess, but they'll probably be the only company to insure you I hope you get a good quote, and if not, hope you can get a quote from another insurance company!
I rung a whole bunch (had a list) and every one i tried had an excuse, dont insure imports, dont insure under 25, etc. Its quite sad really... ended up going with just car insurance third party fire and theft with a fkn ridiculous excess of $2200... my history is a licence cancellation for an excess 0.05 offence and I'm 20. Damn not being able to lie to the insurance companies so they cant discriminate and rip you off!