you can try to take a look on ebay, i did order soemthing similar for my old miners there
otherwise the bitcointalk market is a good place too, there should be everything for mining in that place
Looking at cord looks like it takes a PCI-e and goes to the two poles. There are some who make cables in services. I would agree most likely you could contact one of the cord makes to do a custom one to replace it.
Just make sure you pick someone who uses a big enough gauge wire. Two small of this could lead to problems.
