you can get em from team 108, who can fabricate these cables for you.i had to get a couple online, an already expensive cable, plus shipping, costs you. i'm not sure if team 108 now stocks ready made cables, i've yet to see these.
note thou, if you get the cables fabricated from team 108, request a good quality DB25 head, not those horrible plastic ones that snap apart. This might cost more, but trust me, its worth it. Leant that the hard way.