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
There are some really great options in the budget streamer market now - Raspberry Pi (Allo Digione signature), SOTM sms-200, MicroRendu, MAC Mini and I am sure others. Any suggestions as to which one is sonically superior? 
Once a certain minimum price is achieved, SQ is excellent.  What becomes more important for me isfeatuures, the quality of the app that controls the experience, reliability and ease of use
@ghulamr 

I love the Digione! I don’t think tidal is available through it currently? At least not with the Volumio app I’m using. I need to get back onto forums and see what plans are being made there. It doesn’t process DSD or super high res, but is designed so well that all my tracks, from red book up to 24/192 sounded wider, more detailed, livelier, dynamic, low volume super-clarity ...you name it. I’m running it through a Schiit Audio Uber 2, then NAD C316, into Tekton Lore. You can use WiFi storage or simply plug a standard portable HD into one of the four usb slots. I’m currently just using flash sticks and sounds great. Can’t believe the sound I’m getting from such a (relatively) cheap set up, which has been my pursuit from the get go. Can only imagine how it would sound through your system! Also using an Ifi power walwart, where I did notice an improvement over the Raspi standard plug. The signature is supposed to sound even better with the power supply separation. 
Sorry for the different handle!...I had accidentally logged in as jwricci before.
Forgot to mention/answer your other question about services. There are different formats of loadable (or preloaded) software that can offer plugins through the app (GUI) like Spotify (paid) YouTube (free) or radio. I think there is a roon option that might now get it interfaces with Tidal? Not sure, need to research some more. 

Also, this is a new player from Volumio that looks promising:

https://volumio.org/primo/?mc_cid=7a8e6e28e6&mc_eid=ac725cec3d