super moto and these radiator shrouds

hey guys so iv had the urge to super moto wilbur. the bikes already plated. all i need to know is what size tires and rims i need and also iv seen people fit what looks like cry 450 plastics on the tank. is there a thread that shows how they did this? thanks guys! 

from what ive seen, they fit with the monnier f/tank, or bi italia f/tank, supermoto junkie site should have all the info regards this