Go here...
http://www.helbrakelines.com/
That is where I got mine just a month ago.
Works well.
I must have looked at the contact us page or something because I found a phone number somewhere and just called my order in.
They will want to know how long a cable you want and what degree banjo bolt bends you want on each end.
I think one end is straight and the other is a 35 degree bend at the caliper end.
There are other places to order online too (remember seeing something like "cyclebrakes.com").
Costs around $50 if I remember correctly. And product is guaranteed for one year for defects or leaks so I was told.