Probably all spiney eels, except peacock spiney eels, can and will eat kuhlis. The peacocks are much smaller than the others, and therefore have smaller mouths.
I plan on getting some peacocks for my tank, and I also have kuhlis. I was told there shouldn't be a problem with these two species, and some people have been able to keep them together without problems. Just to be safe though, I have moved my kuhlis to a different tank so I won't be taking any chances.