I guess it depends on what you are configuring. ArubaOS 8.0.1.0 and ArubaOS 6.5.1.2 are still early deployment versions.
I would suggest to stick with the latest general deployment, when configuring a (bigger) production environment. In that case it would be ArubaOS 6.5.0.3.
If it is a smaller environment or a pilot / proof of concept environment or an environment with a very basic configuration, I would suggest to test ArubaOS 8.0.1.0.