Looking for NAS recommendation

[pomme4toi]

Looking for recommendations from the experts pls! My key wants:

General Wants
- Needs to work well in a Mac environment
- Needs to have good, friendly UI
- Good security to prevent unauthorized users from accessing my home wifi network
- Needs to create a personal cloud that lets me access my content from away-from-home locations

Specific Want
I have about 3TB of audio and video content in iTunes on my Mac. Some is purchased video content from the iTunes Store, H.264 m4v files with DRM. Some is my own video content, also mostly H.264 m4v files, but with no DRM I want to copy (not move) my iTunes library onto the NAS, then use the NAS as my cloud streaming service. I want to stream iTunes movies from the NAS to my iPad when I am away from home, so the NAS has to be able to play DRM-protected iTunes movies.

I'm looking for a 4TB 1-bay NAS. I've been looking at the Western Digital My Cloud, the LaCie Cloudbox and Sinology DS115J. They all seem to fit the bill, but in all cases, the product descriptions do not explicitly state whether they will stream DRM-protected content to an iOS device.

Looking to your recommendations! Thx