An Windows unattended installation has been a common thing for many, many years now. This is fully documented on TechNet and many other resources.
When you say…
The only part I am missing is the automated Windows install.
What exactly are you looking for that is not already provided by TechNet resources relative unattended Windows install?
The Windows Deployment Services (WDS)…
Windows Deployment Tools Technical Reference
Utilizing Windows Deployment Services in Windows Server 2012 R2…
…functionality is the “supported” method to do automated installations of server and client OS’s in a fully-featured way.
If you don’t want to go that heavyweight you could look at building unattended answer files
that will be used to automate the setup process. This is also a “supported” process, but you’re more “on your own” and it’s not a completely integrated solution. (You sound like you’re comfortable writing code so this might just be up your alley.)
Automatic Installation of Hyper-V Hosts with Windows Server 2012 R2
This is an unattended.xml Installation File for an automatic Installation of Windows Server 2012 R2 Hyper-V Role.The unattended file is generated through Windows System Image Manager. Download the File, place it in a root volume during setup, i.e. a USB Media. It will be detected