Well, as of today, my streamer is an old (discontinued) Chromecast audio with a digital out to a DAC. That’s probably the closest thing to bit perfect I have, even though I suspect that little thing resamples everything to 48kHz.
As far as of DDC, I’d do using regular optical Toslink cables. Already have a cheap’o FiiO K3 doing that actually. Since I only use Youtube music service, I guess I’m probably 90% there (or more). I still see a lot of gear using that format so it should be a fairly inexpensive system to build.
YMMV, as usual. Cheers.