Actually, for a short length, virtually any coaxial cable that's functional will work well as a digital coax link. I used a 40 year-old, yellowed, cracked audio interconnect I bought in the mid 60's for a digital coax link as a test and it worked fine, at least to my ear.
When it replaced it's ugly but with a newer cable for cosmetic reasons. I heard no difference at all.
IOW, try what you have lying around. You might be surprised.