What's my ideal music server? Read and recommend please

Right now I use a MacBook Pro as my server, and it drives my DAC. My MacBook Pro is getting cranky, it's storage is so full I don't have space to do a current Mac update and I am beginning to think better sound quality can be achieved than a MacBook Pro via USB to a DAC. I use JRiver media center, v.27, and right now, my JRiver and MacBook Pro aren't working properly together as I keep loosing the proper MIDI setting and get no audio output.

I'm aware of the Aurender N100H. I know that uses a USB output and I'm starting to wonder if USB is my best bet. Then I see the Aurender N100C which has a digital coax out, but that output is derived from the USB, so what's the point?

My wish list- probably no less than 2 TB storage; got to be easy to use in terms of getting music into it and playing music (downloading music from say HDTracks to JRiver is the bleeding edge of my technical skills); sound quality has to be first rate. I would also be interested in a server that has a BNC output, as a regular coaxial output can never be a true 75 ohm connection but a BNC can be. 

So- what should I have on my short list? Recommend away please, and thanks-