I agree with Anoop. If you are building your own, and only a few, then Windows 7 Home or Professional is the way to go. You do not need Professional for any extras, but several of the forums out there are saying the professional is more stable for some reason. This is regarding Video Editing. You will probably be alright with Home. The Embedded is not cheap if you are only doing a few machines, unless you know someone who is able to get you a copy. As I understand it, there is a license fee for the compiler that is expensive and you need to meet certain guidelines to get the license. That is usually left for the computer wholesalers who sell a bunch like Media Signage does or car manufactures. Stay away from Windows 8 for now. So far there is no data to show how it can handle Adobe Air and the MediaSignage Application. It will probably be just fine, but I would hate to see it become another Vista mistake.
I hear Logmein is good. I have not used that in a while as I now use TeamViewer which I like as it groups my machines together based on which network/client they are with. Logmein might do that as well. I also used to use Tight VNC.
Also, Did you already purchase the NUC? I do not believe you will be able to find a price cheaper that what Media Signage offers, but if you do, please let us know. If you are not going with the MediaBox 200 V2, there are some new ones coming out in April that are i5 and possibly i7 models. I am waiting for the i7 to test it. There have been some mention of over heating issues. These are typically with the version that MS does not sell which is the Red unit because of a SSD. Intel has since changed what drives they use now. Also it depends on how much use the Wifi card gets if you opt for one. If you do get the Wifi model, I would suggest placing a heat shield between the SSD and the Wifi Card.