I did the M40 flywheel conversion too.
All you need is the M40 flywheel, the M40's shorter flywheel bolts, and a M40 clutch and pressure plate... it all just bolts in.
Personally I didn't notice a huge difference with a stock M40 flywheel although it was about 2kg lighter than the M40 parts. Probably best to remove another 2kg or so from the stock M40 flywheel if you are looking for a big change.