Your linked cable (You typed "a 7 inch, 9 pin to 9 pin, firewire 400 cable," but I assume you meant 6 pin to 6 pin.), on the other hand, prices out at no less than $15.95 + $9.90, and that's awfully pricey for what is pretty much an experiment.
That's what happens when I get in too big a hurry. They do have 6 pin to 6 pin cables, but at about the same price. As I say, you get what you pay for. Cheaper cables can and will work but in general more expensive cables work better. It all depends on what compromises you are willing to make.
