We've just launched a beta of
Appveyor - a tool integrated into Visual Studio for deploying .NET apps to your Amazon cloud.
We designed Appveyor with real-world apps in mind like Kentico CMS. I think for Kentico you would be good to go with "Small" instance for website and another "Small" instance for SQL Server. With Appveyor you could put live, staging and developer websites onto one AWS instance or have separate instance for each of them that use shared SQL Server instance.
Let me know if you have any questions or feedback.
Disclaimer: I'm a developer of Appveyor.