The second one on the list, the Pisound, has two DIN ports (one in, one out) and looks like something that you can buy.

https://blokas.io/pisound/

Pisound is an ultra-low latency high-quality sound card and MIDI interface specially designed for Raspberry Pi pocket computers.

Equipped with 192kHz 24-bit Stereo Input and Output driven by the legendary Burr-Brown chips, DIN-5 MIDI Input and Output ports, user-customizable button and bundled software tools, this little Raspberry Pi HAT will bring your audio projects to a whole new level!

And seems to be pretty much ready to go as soon as you get it:

Setup is Eaaasy!

Pisound mounts directly onto Raspberry Pi, no additional power adapter or soldering is required.