Again , a reminder that you will not be able to copy commercial video Blu-Rays. I believe the loud anti-DRM minority in the FLOSS world has effectively delayed support for those , at least FLOSS Blu-Ray DRM support only began to evolve few years ago (and still is in its infancy).
Note that the enclosure is only 2.5" big , you might want to get a 3.5" enclosure instead. Furthermore it is unclear how the thing will power power-hungry drives like optical ones ( getting the current exclusively from the USB port would strike me as suboptimal for use with a Pi).
Raspbian should be the Operating System of choice. Note that commercial burning software "for Linux" has little chance of actually running on it even while
Raspbian is a proper GNU/Linux system , but free software exists for data (not video !!) Blu-Rays.
• Don't like the board ? Missing features ? Change to the prosilver theme ! You can find it in your settings.
• Don't like to search the forum BEFORE posting 'cos it's useless ? Try googling : yoursearchtermshere site:raspberrypi.org