Will whatever copy i get of crysis 2 will there be a 2d disc and a 3d disc inside the cover or will i need to buy the 3d in like another special edition or something?

crysis 2 will there be 2d and your computer with nvidia 3d vision you can convert crysis 2 to 3d

It will be on the same disc. If your system (PC, PS3 or XBOX and monitor) is capable of 3D you can choose it in some menu.
So the game itself will be possible to give you 3D if your system is capable. It is not converted from 2D to 3D by the system as described above.