Two posts above your post:
Alles anzeigenHI,
I sorted a little bit the Storage,
now you will see a "Current" folder for the most actual kernel I build on this source tree.
If you are intrested in older kernel Versions, you can find them in the "Old" folders.
Current 4.6
Current 4.5
Current 4.4
I suggest to always install the headers as you may need them to compile additional features like vBox driver ....