You can add the Singxer SU-6 to the list provided by @mbolek. Most of those provide adjustable pin settings for I2S and they also provide other various outputs such as AES/EBU and S/PDIF via RCA and/or BNC.
The Holo Red mentioned previously has received good reviews for sound quality (as did the Singxer) and the Holo Red can also be used as a stand-alone streamer, which most of them can’t.
You should take a look at this review.