For some reason the documentation on the Xamarin website isn’t as clear as it could be for doing all this.
The first step to realise was that Visual Studio needed to be updated with the new SDK Manager as the old one has become obsolete. Following these steps get this bit done
Once installed you’ll be able to go in Visual Studio 2017 to Tools > Android > Android Emulator Manager and it will open the below. Add a new device to get an Android 8 Oreo emulator. We had to restart this program to see it come in to the list! Just like binding to a listview in Xamarin LOL.
Lastly we had to disable Hyper-V to get it to run as there was an error! Open cmd as Administrator and copy and paste the below…
dism.exe /Online /Disable-Feature:Microsoft-Hyper-V-All
And here we have an Android 8 Emulator running Oreo!
Here is what the Quick Boot is like… Very fast.
UPDATE: (08/10/2018) After the latest Visual Studio Update (15.8.5) We received an error “Incompatible HAX module version 3,requires minimum version 4”. To fix this we simply downloaded the latest installer below and this solved the problem!