I would concur with Madmax regarding the choke. Mine does not have one and I can start the car in 0 Celsius (30 degrees Fahrenheit) weather; just pump the gas twice before starting it and then feather the gas until it is warm. I have an electric choke available to hook up to mine, but I am waiting to see if I really need it. Based upon your car number it probably has the 8.8 IRS with limited slip and a 3.73 to 1 ratio.
You should get a SCOF membership and contact Mike Stenhouse at Second Strike (
Second Strike - the Superformance Owners Group) to order a manual. They have a wealth of information.
98 octane is more than most of us here in the states have at our disposal and should be fine.
Sounds like you have one hell of a car, enjoy it.
Jim