Modify a kinect - Reconnect the two cards
Assuming you can get connectors of the right pitch / hole size (Which should be fairly easy) you can use an IDC (Insulation Displacement Connector) connector and cable (sometimes referred to as a ribbon cable). The biggest mistake people make is getting the pins and wires to align correctly (It's easy to turn the connector 180 degrees and so you no longer have a 1 to 1 pin connection) so buy 2 of each connector and twice the length of cable. 

The other possible down side is interference affecting your cable. You may have to shield it. But for this small length is should be ok.