From what I have read here and other forums if you want to reduce rotational weight flywheel and driveshaft would be better ways to go,,
Some have said if you get everything "too" light it takes lots of reving to and clutch slipping to get going. After all my reads I decided to use lightweight flywheel and alu. driveshaft and "stock crank pulley" and not have to worry about possible bearing problems and a touch better driveability.