I have no idea what level of polish should I get?

This is based soley on lube and amount of work you intend to put into breaking in the car.

Graphite Lube – 3K, with proper graphite break-in

Oil Lube – 100k

If you are simply going to dust with graphite and race, not doing a BREAK – IN for graphite – 100K will give you the least amount of friction for multiple races