I understand wanting a "cable in a kit"

I don't know what the cable looks like on the ends where itslides into a slot that you can't easily duplicate.
mounts up; there's probably some doo-dad clamped on that
But if you've got both mounting ends, why not just go to home depot, get some cable and cable clamps, then tighten it down? (strip the insulation off where you clamp on). You could even throw in a turnbuckle and make it adjustable.

Then toss some paint or something on it if you're worried about rust.

It's not rocket science, it's not even automotive engineering science. It's a cable.