Looks good to me. Some may argue to get an M2-ATX Power Supply instead, but that's personal preference.
I have an M2 and it's been great to me so I certainly recommend it but I'm sure the OPUS is great as well; many people use those.
I would suggest getting some type of wireless mini keyboard as well. I had a wired full sized keyboard in my back seat for the longest time and trust me it's a pain to use even the few times you do need to use it.
Otherwise, looks good!