Hi there,
I think you should take the same diameter (EBS' engineers though about it back in the days) as existing on your car and every steel cable would be good, (now, with all the industry relocated in China, unfortunately, all products are the same...) just find the good "hook" for putting it on situation.
And here you go!
On my EBS those steel cables are still working normally, so no need to change those now.
Good luck!