I had Redco make me custom cables for my rack drawer and GCX. It wasn't cheap but it was worth it.
I did stereo Mogami cable (TRS) to halve the size of the pigtail with two straight end connectors on the GCX side and two of the shallowest right-angle connectors they had for each cable. If I remember correctly, I did eight pairs at 42-inches each and it worked well, plenty of room for the drawer to open. Cost $250 or so. http://www.redco.com