Budget Music Streamer


I've been trying to get my head around best sound out of a budget streamer. All my CD collection is now in my portable 2TB hard drive as FLAC files and I also have subscription to Apple Music (large playlist). Currently using Apple TV and Airport Express (airplay limiting to 16 bit/44.1kHz) and Apple TV streaming at 48kHz. I have a revealing system and know I can get better sonics by upgrading my digital source. Unfortunately I have been blessed with a good ear for music.  

There are quite a few options out there, each having it's limitations, specially the ability to play Apple music directly from iTunes using a remote without limiting the sampling rate. Do I consider a Mac Mini or build my Raspberry Pi source? Will I get a spdif connection (preference) out of the two? Is there remote control capability to view playlist (I don't intend to hook up a monitor). Or is there a better solution out there for both listening to FLAC files on hard drive and streaming Apple Music? I plan on selling my OPPO player - no use to me, to fund a better DAC (schiit Yggdrasil or BorderPatrol) - hence the digital source is on a budget. Experts chime in..

Simaudio W5 poweramp
Von Schweikerts VR4 
OPPO 105 
Apple TV (using Kanexpro HDMI de-embedder to extract audio - coax in DAC)
Airport Express (optical in DAC)
Benchmark DAC1 (no USB) - used as preamp
Marantz AV7701 preamp
Morrow Audio interconnects 
128x128ghulamr
@headphonedreams better to buy the Allo Digione Signature or build one. Building one will not be all that cheaper but more fun. Can you share your build? 
I put together a digital streamer using Raspberry PI 3B, Hifiberry Digi+ Pro and a good linear power supply.  This is streaming my FLAC files (in my home SAN on WD MyCloud) over WiFi to Rotel RDD-150 DAC.
Sound is great.
I also have 2 additional Raspberry PI 3B DACs using ALLO Boss 1.2 and HifiBerry DAC + PRO for Bedroom and Pool areas.  All these are running Volumio on my IPhone and IPad.
A nice Raspberry based Streamer (or a DAC) will cost you around $150 including Raspberry itself, DAC or Digi Power Supply, and a nice case.

If you put together a DAC (either ALLO or HifiBerry), it is important to have a good and quiet LSU (Linear Power Supply) with a toroid or R-Core transformer.  You will need to supply Analog part of the DAC separately than digital side.  I can give you more details.  It sounds complex but it really is not, and the satisfaction you'd get from building it yourself is priceless..
@pc997 do you have a write up the build? I am hoping there are advantages building one than buying (easier)? Do you have a write up. Have you compared the sound to Mac Mini? Thanks. 
Would not analog solve all these issues? Less fatiguing, warmer etc whatever else mentioned, lol. Kidding of course (sort of), but to me, trying to change something that is inherently digital to sound like or more like analogue seems like a lot of work and expense, when you could just go analog, but hey that's just my reasoning, I'm an analog junkie🙄