We made our own custom sync cable. I posted on the HD24 Yahoo! group about this, I'll try to dig it up again. Yes, you want 4 pair, individually shielded cable.
OK, here's what I posted there:
"The connections are one-to-one. Use a 4-pair
individually shielded twisted pair cable with an overall shield and
drain wire. We used a Gepco audio snake cable with 24 gauge
conductors. This cable is kind of stout so you might want to find one
with thinner jacketing or smaller gauge (although I wouldn't go less
than 26). Here's the pinout:
1 --- 1 overall drain wire
2 --- 2 \ these are paired
6 --- 6 /
3 --- 3 \ these are paired
7 --- 7 /
4 --- 4 \ these are paired
8 --- 8 /
5 --- 5 \ these are paired
9 --- 9 /
Tie the individual pair shield drain wires to the housings on each
end. "
OldHouseScott