Exedy is a single disc. not a dual (will be coming out soon though) You can also use it with your stock flywheel. Does not require a billet. They also only make a lightweight steel flywheel too which will work on McLeod and Exedy products.
Fine if they are not out yet, but they call it a twin on their website and in this video..
[nomedia="http://www.youtube.com/watch?v=fSRQN7_iRWU"]Exedy's new Cerametallic Twin Plate Clutch Kits released at SEMA 2011 - YouTube[/nomedia]
and it looks amazing too bad you can't have it visible in some way its a thing of beauty.