HDMI (i2s) recommendations for Denafrips Gaia -> Terminator

I have a denafrips gaia on the way to use with my Terminator DAC and I'd like to connect it using I2S since I've heard that this is the best sounding method. 

Any recommendations on a good sounding HDMI cable? I'm considering the AQ Firebird 48 which is fairly pricey and is probably the maximum I'd want to spend ($1299 for 0.75m length).
Thanks for the pointer. That one looks like a possibility. 

No one else using i2s over HDMI?

I've also looked at the Tubulus Argentus https://www.highendcableshop.com/product/tubulus-argentus-i2s-cable/ which has some recommendations on WBF. 
I've tried AQ Carbon, AQ Vodka, Phasure hdmi i2s, tubulus argentus, and am now using pink faun i2s. The tubulus is a really good cable and I'm selling my 1.5m length if you are interested. I also have a short 0.7m length of phasure i2s up for sale too. 

Thanks @docroasty. Do you have any comments on the differences between these cables. I had not heard of the phasure or pink faun cables before. 
Phasure is the most bang for buck. Fantastic sound given the price. Looking back, I would have been completely content with a whole loom of phasure et3, lush3 and hdmi2 cables. However, curiosity got the better of me and I ended up spending on more expensive cables. 

Tubulus is detailed, with amazing transparency and clarity. Nice low end punch too. The most engaging cable I have tried. 

Pink faun is a bit more reserved up top. Smooth and slightly recessed compared to tubulus. Also a bit thicker mids and mid bass, with slightly less punch down low. 

I chose the pink faun for my system as it suited my components and headphones better. But I preferred the tubulus when I was using it with my holo spring 2 dac (which I have sold). 

Thanks for the info. I'm tempted by the Tubulus, but I'm hoping to use a shorter length since I've heard from other Denafrips owners that longer connections can have issues. 

I assume that the AQ Vodka you had was not the Vodka 48? How would you compare this to the Tubulus? I'm not considering the Vodka, but as I mentioned in my OP, I am thinking of one of AQ's higher end cables. But I would just-as-soon spend less if there is a better (or at least comparable) option for less money. 

I've never really been an AQ fan (from a price-performance perspective), but their volume (and factory machinery) allows them to make cables with very high build quality, and I think an i2s cable is going to be particularly sensitive to this since i2s was never intended to be used for box-to-box communication and has no error correction. 

I have an AQ Diamond USB cable that does sound better than other USB cables I've tried.
Actually it is the vodka 48. Im not using it for audio primarily though. I'm using dedicated i2s hdmi cables mentioned above for music. The dedicated hdmi i2s cables can't be used for video. 

I also currently have the denafrips gaia on loan lol.. But not using a termy or termy plus. Hdmi i2s up to 2m is fine. I was using the tubulus cable between the gaia to my rockna wavelight dac with no issues. 
That's good to hear that you didn't have problems with the longer tubulus cable. Did you have a change to compare the Vodka 48 to the Tubulus?

My Gaia should arrive Monday or Tuesday and I'm going to try it out with the AES cable I have first, and maybe a cheapo HDMI cable, before I decide how to proceed. 

Thanks for your comments and recommendations. 
For I2S, length of the cable is the most critical performance factor. You want to go very short e.g., no more than 6 inches.

Sure, a longer cable will work, but the I2S standard was designed to communicate PCM audio data between integrated circuits in an electronic device, not between external peripherals.

Longer cables can result in differences in propagation delay between the clock line and data line, which can result in synchronization problems between the SCK, WS and data signals (mainly at high sampling frequencies and bitrates).

Since the I2S bus doesn't have any error detection mechanism, this can introduce significant decoding errors.

I am aware of the issues with i2s, and agree that keeping the cable length short is desirable.

Most devices that support I2S between boxes (including the Denafrips products) use additional buffering (generally LVDS - low voltage differential signaling) which can support cable lengths of 2-3 meters.

As you point out, the longer the cable length, the more likely that slight differences in cable length and propagation delay will cause skew between the clock and data signals. Also, LVDS only has a modest amount of common-mode noise rejection, so the longer the cable, the more likely external noise will interfere with the signal. 

With my DCC and DAC on shelves one above the other, I can get away with a 0.75m cable (even one that is fairly stiff), so that's what I'm looking for.

I'm a little leery about buying a hand-made cable since the consistency of the individual conductors lengths, twisting, and shielding will all have an impact on the amount of skew between signals.

I think this is the only type of cable used in audio where clock and data are transmitted separately and where there is no error detection/correction, so example-to-example differences (particularly for a hand-made cable) may be more significant for this type of cable than any other type of audio cable. 
I've had i2s cables measuring 0.7m, 1m, and 1.5m and can't say I've had any issues with any of those lengths. 

If it makes you feel better, go for the AQ ones. They're built well and should do the job. But I think u may miss out on some really well built artisan cables, lovely music, and a more personal/human transaction and after care service.

I really enjoyed the whole transaction process between the guys at pink faun and highendcableshop. They were a pleasure to talk to and deal with, and very forthcoming with information.

I guess, at the end of the day they are just cables that will probably cost a fraction of your entire setup. So may be worthwhile to try a few out and settle on whichever you like best. Check around for return policies too. 
@docroasty - I appreciate your input. It does give me a bit more confidence to try one or two of the artisan cables. At least many of these are specifically intended for use as an i2s interconnect, which is more than you can say about AQ. As you point out, they aren't that expensive in the scheme of things, and are considerably less than I'd pay for the higher-end AQ cables. 

For now, I'm going to hold off on making a decision and see how well the Gaia works over AES to my Terminator. I've got a bunch of generic HDMI cables hanging around that I may try just to see how well it works. 

Still hoping my Gaia will arrive Monday, but Fedex hasn't confirmed a delivery date yet.
@docroasty - took your advice and ordered a 0.75m Tubulus Argentus. Thanks for the help. 

My Gaia arrived yesterday, so I've only got about 24 hours on it, but it's definitely an improvement. Imaging is sharper, a bit more detail, and bass has more weight and texture. I can't wait to see what it can do with a better i2s cable. 

- Jay
@jaytor good choice! Enjoy! The tubulus is a really nice i2s cable. U can go higher up the price ladder but from this point you're at now, I think there is no better, just different.