Do I need to buy a specific Sony ilink firewire cable to go from my pd 170 or can I just buy any firewire cable that fits?

Any that fits. Just buy a quality cable, not a junker. Reason? A few years back, one of the cable manufacturers built some firewire cables with reversed wires and that ruined the firewire input/output circuits of a few cameras.

Another thing to consider... some cables are made from really stiff wire which can place a strain on the 4-pin camera connector. That can also be a problem with some s-video cables...