Hi mate,
I'm 28 no points with a 380bhp cosworth and I am paying £580 with all modifications declared. I used a company called need to insure which I was recommended by a friend of mine.
All I had to do was join the RSOC and take a few photos of the car to send back to them.
The number is 01623720081 i'm sure they will be able to help you.
Good Luck