HDMI cable for I2S

Well, the old upgrade itch had to be scratched, and even though it's a little behind the times now, I've invested in a refurbished PS Audio PWT and a used PWD MKII for my redbook CDs. The former is currently being assessed by the folks at PS Audio because it seemed unnaturally noisy when I received it, and the DAC hasn't actually arrived yet but should be here in the next day or so. So now that I can connect the two via HDMI using the I2S protocol, I need to stir up the old question of whether I'll get any advantage by shelling out some money for a high-quality HDMI cable? There's been a lot of verbiage devoted to this debate, but I would like to hear some real-world experiences. Have any of you compared different HDMI cables in this application, and did it make any difference? Of course one can carry this to its logical extreme, but I was thinking more along the lines of Audioquest Carbon (I use the coax versions of these in my system and think they're very good) or even their very modestly-priced Pearl cable. There's a Wire World Silver Starlight 7 available here on Audiogon just now, but I just can't work out whether it would make an audible difference over a standard (read: cheap) high-speed HDMI cable. Thanks for any input you may have on this.
BTW, speaking of logical extremes: http://www.audiolab.com/audioquest-diamond-hdmi-digital-audio-video-cable-with-ethernet/?utm_medium=...

I’m asking a very naive question simply because I didn’t understand the answers given above. So my apologies at the outset 
1. Can I run an hdmi cable between the Oppo103D and my PerfectWave DAC? Use the hdmi out to I2S input on the DAC? Will it pass the audio signal properly?
2. Is digital by hdmi better than coaxial?
 Thanks for your replies 🙏
HI Johnread- the Oppo outputs combined audio and video thru the HDMI output, while the input for I2S input on the PWD is ONLY for digital audio, so NO- connecting the two via HDMI cable will NOT work.  
Recently purchased a DH Labs USB cable; completely annihilated the SS7 -in another league altogether.

Johnread57: I did a little poking around about the Oppo and discovered that while it doesn’t support the I2s protocol, but you can buy an add-on card that will enable I2s output via HDMI. Here’s the link: www.oppomod.comThey have a number of different cards, so scroll down to the "I2s Card Upgrade." They confirm that it’s compatible with PS Audio but I’m not sure if it’s compatible with your particular Oppo model. I have no experience with this company, so can’t comment on their quality/reliability.
My own experience with the PS Audio PWD II is that the I2s/HDMI connection was indeed significantly superior to the coax connection.

I2S is the way to go. And it’s not rocket science. I2S is the standard protocol of all redbook 16/44.1 and is how the data is prepared prior to the output stage. PS Audio just decided to use that data in its naitve format and send it on from player to DAC unchanged. HDMI is simply a good conductor for multiple data transfer in a single shielded format. It it’s good enough for video, it’s good enough for audio data. I2S always sounds better than coax, USB or optical. There’s no combining and uncombining of clock and signal data. Less chance for data anomalies.