RCA Phono Interconnect Under $400

Here ya go!

If the cable does not have a ground, you can just make one. 

An RCA to RCA cable will definitely carry audio ground. If the tonearm or TT need ground to the phono, any old wire will do.

when I bought my long tonearm, the maker essentially insisted I buy this Ortofon

I did, but frankly I do not hear any difference comparing several, including inexpensive one, Acos Lustre's OEM or Custom Pine Tree cable I had made.

I would say, buy from a source that accepts returns, try, keep or return.

I changed my interconnects to Locking RCA connectors

these, or others

If you cannot find ready made, you could have Pine Tree make you a cable: rca/rca/ground/locking connectors, your desired length.

I bought two of these 3 wire Component Video Cables, got 3 pairs of locking and each pair it’s connector’s a different color.

As others have said, buy a separate, or get a spool of green coated wire and make a separate ground wire with crimped spades.

https://www.google.com/search?q=green+ground+wire&rlz=1C1JSBI_enUS1081US1081&oq=green+ground+wi&gs_lcrp=EgZjaHJvbWUqBwgAEAAYgAQyBwgAEAAYgAQyBggBEEUYOTIHCAIQABiABDIHCAMQABiABDIHCAQQABiABDINCAUQLhivARjHARiABDIICAYQABgWGB4yCAgHEAAYFhgeMggICBAAGBYYHjIICAkQABgWGB6oAgCwAgA&sourceid=chrome&ie=UTF-8