I'm looking for recommendations to implement a new entertainment setup.
I intend to build a server for this, but it will need to operate mostly without a connection to the internet (when I need to connect, it will be for short times using a Netgear AC785 docked in a DC113A) as the "deploy location" does not actually have an internet connection. I will have a 'proper' internet connection during setup.
Any suggestions on capable, yet inexpensive hardware for the server would be greatly appreciated along with thoughts on the best setup, software and configuration. I have a Nvidia Shield TV (16GB) that I will attach to the main TV which can serve as a client device and allow some offline gaming). I also have a couple of Raspberry Pi boards that I can use (likely for client devices).
Ideally, what I am trying to achieve is something capable of:
- media server
-- likely running either Kodi or Plex for local video playback (from USB/microSD...) to iPad/Android tablet/Kindle Fire/or client attached to 1 of 3 TVs;
-- the ability to stream to more than 1 client simultaneously would be a real advantage (e.g. 2 TVs or 1 TV and a tablet watching 2 different programs at the same time)
-- a bonus would be to be for tablets and mobile phones to upload recent photos to the media server's storage for local sharing (and maybe a batch upload to Dropbox or Smugmug at some point via the 4G connection or hotspot tethering)
- minecraft server
-- If possible, I would like the same server to act as a local minecraft server for my children to play together (locally) from their tablets; no need for outsiders to join and no need to access the server/worlds from beyond the vicinity of the LAN
Suggestions appreciated. I am hoping to take advantage of some end-of-year sales for components.

Thanks!