Raspberry Pi based source for in-car use

Hello everyone.

I'm currently working on an upgrade to my car audio system's source and I'd like to experimenti with a Raspberry Pi based solution for music playback and streaming.

My plan is to try out the various OS available for bit-perfect playback (Moode, Volumio and PCP) at home to see which one I prefer. The RPi will be operated 100% of the time via a mobile device connected to the car's WiFi network, so the ease-of-use of the various OS will be of primary importance, together with stability and resiliance. I don't need a DAC, (conversion managed by my DSP) just a reliable and high quality USB/digital player and transport.

Funtional requirements are pretty simple:
  • bit perfect playback of tracks stored on a USB stick and/or SSD HDD connected to the RPi with output via USB (then connected to an XMOS-based converter like the Hecate ARmature or SMSL PO100 Pro) or Coaxial SPDIF using a high quality transport HAT for the RPi (TBD based on performance and cost of the 2 alternatives)
  • ability to manage an auxiliary input coming from a Chromecast Audio connected via optical for streaming duties (I already have an iFi iPurifier2 for jitter reduction installed in the car)

I've ordered a RPi 5 4GB board and am starting to look around for solutions to get the optical signal into the RPi (don't need to control the CCA from the Pi, just the signal); unfortunately I'm not finding much info regarding compatiblity between the digital input HATs and the various OS, so I'm writing here in the hopes that someone could maybe provide some feedback on a proven solution.

So far I've found a few possible alternatives from Hifiberry and Ian Canada, at different price points, but that's pretty much it. Did I miss anything out there on the market?

If anyone has any pointers to help me move forwards with this project it would be much appreciated. :)

TIA