I am using Windows Server 2008 R2 Box for my development purpose. I could not see any hibernate/sleep option in the shutdown options. What could be the reason to hide these options for a server machine?
Have you installed Hype-v role? If yes, then Windows disables the Sleep and Hibernate options. You will need to make the Hyper-V service start on Demand for Sleep and Hibernate options to be re-enabled.
Refer to this blog post for details.