LVDS cable between a camera and a FPGA
I'm gonna offer options


Serial Attached SCSI or SAS


Basically glorified SATA. You can get 8 differential pairs, 6Gbps each, for $8. Perhaps not exactly what you want, but there are many options, so maybe...


PCI-Express


You can get PCI-Express riser cables to make a PCI-Express card work outside of the PC for debugging. There are many models, depending on how many lanes are needed, so you can actually pick the number of differential pairs according to your needs. Some have fancy twinax diff pairs. Plus it also carries power and various signals. Problem is, it comes with a PCIExpress connector...

Then, there is this, notice the flat flex cables are probably rated for PCI-Express bandwidth, and they are connected to both boards with nice connectors. 

You could also get a "mini pci-express riser."


DIY


You can get a 25cm x 5cm double sided flat flex manufactured to your specifications for about $130.

Kind of expensive (but we used to pay that a few years ago for double sided which is like $5 these days). Maybe you can find a cheaper source.

This will be the most flexible option, as you will be able to get exactly what you want, choose your connectors, or even solder both ends directly onto your boards if you feel like it.

You can also buy pre-made flat flex jumpers, but then you'll probably be stuck with the extra-filmsy connectors which break if you look at them wrong.