I2s versus AES/EBU to connect an streamer/server to a DAC?

Check with your DAC manufacturer as to which input is preferable.  It’s most likely i2S, and if that’s the case a DHLabs HDMI 2.1 is a solid recommendation, but use the shortest length possible as i2S wasn’t designed for distance.  Best of luck. 

What @soix said. ✅️

@soix +1 with the caveat that not all I2S is HDMI…some are rj45/ethernet type cables. Depends on the brand(s).

I2s is the best way to go because it offers greater resolution and can handle DSD which SPDIF usually cannot.

I would only use I2s if it is a native output to input, otherwise USB or AES would probably be better.

IME RJ45 is preferred because of the larger conductor size but I found no benefit in going below 0.5m in length, whether HDMI or RJ45. PS Audio recommends 0.5m.

I had excellent results with WW Platinum, Furutech was good too but darker.

I experimented with connecting my Lumin U1 streamer to Denafrips T+ DAC via SPDIF, USB, and AES. I found AES sounded the most natural and full throughout the frequency spectrum, and was best across all types of music for my ears.

As with many things audio, it's a lot of trial and error. I do want to try I2s at some point.