You can save some money by going for a single mass flywheel. This will be lighter and allow your engine to spin up faster but may introduce chatter.
Not sure if you'll be able to reuse your dual mass as they can be quite tricky to machine.
Some people also go for a 550i/335is clutch which is compatible and can handle some more torque. An OEM clutch will have easy takeup
http://my1series.com/2015/03/23/335i...lutch-upgrade/