Tvheadend

Being of modest programming skills (novice java developer, at that), I ask your help in selecting an OS for my targeted Kodi, HDHomeRun, RPi2, and TVHeadEnd client/backend system. Maximum performance requirements are no more than 2 1080 streams recording and/or playing back at one time. I am already running various other client and prototyped configurations, and am trying to settle on my final target;

Clients:
- Amazon Fire TV, Kodi: Works fine, no issues
- Linux laptop, Kodi: Works fine

Prototypes:
- Kodi, WMC: Currently my working backend, though on a laptop I need to return to other full time family purposes.
- Kodi, NextPVR: On Dell Mini 10, works but is slightly underpowered when recording and/or playing back two 1080 streams (playback means sharing via DLNA in this case).

I started with OSMC on the RPi2, but am not finding a clear understanding on the state of packaged TVHeadEnd from the app store (4.0.7). It appears one must go through a build process for installation (and each upgrade).

So I am eliciting recommendations on which OS I should adopt for the above targeted system (for a person of modest programming/admin skills).