If you only use your scooter for short sprints the standaard radiator will do. If you want to race with your scooter on the track even the malossi radiator won't do in the summer time. The Runner180 radiator is smaller then the malossi one.
Ideal temperatures for these cylinders are 50-60 celcius! I you want to be able to keep the coolant temperature at this level under any circumstance you need a malossi radiator + the standard radiator or something much bigger than the malossi.