Digital Interconnects - Which one is the BEST ??!!

Chord Clear way makes a very nice digital coaxial cable. 

There is only "best" for you. Try them all.

As you can see, it depends who you ask - for me, optical has typically worked better than coax in the past 20 years.

I can confirm that a "regular" RCA interconnect is not the same as an RCA terminated coax...though some work great as a digital cable and some don't...

As in most things in audio it depends. The only real generality is that optical is consistently an inferior connection.

You will find volumes on the subjects of interconnects here. Given what you have said, I recommend you completely take the question off the table.

An audio system is composed of components. It is the sonic character of those and how they interact that is hugely more important than the connector. The digital or analog source, DAC, preamp, amp, and speakers determine what the sound is going to be like.

Then… when the 85% of the work is done and you have a system that is of the character you want… hooked up with the connectors that came with the component, it has had a few hundred hours of use… you know what it sounds like inside and out; then it is time to start asking which brand of connects you should use… which interconnects might effect the sound in a more favorable way.