Really looking forward as to how this turns out.
Since I don't have a dedicated Amp, but rather a DAC-AMP all-in-one, I decided to 'replicate' this idea with a single Raspberry Pi 3 and Volumio as the OS DAP (Digital Audio Player) hooked via USB to the DAC.
In my limited understanding, this reduces the need (or at least bypasses most of the advantages) of a linear or other expensive PSU / filter. Another advantage is that I don't need extra modules on the RPi as the DAC portion is being handled by the external DAC.
I am curious as to what OS route you are taking? My guess is that regular distros with Plex media server would have the tendency of doing internal resamplings, and other factors. On the other hand, using this ground-up bit-perfect distros like RuneAudio, Volumio, Moode, etc., would be a 'cleaner' and faster way of achieving better audio signals to the DAC. Also requires a lot less configuration and allows for other neat features as having AirPlay built into the OS, pre-programmed radio stations, etc.
Any thoughts on software? What am I missing? Interested in insight regarding that part of this amazing PC-DAC you are creating.