Digital BW, The Print

I have a iLink (Firewire) connection on my Sony and my scanner (2450) 
has one. I was at a Best Buy today and decided to get a Firewire cable. 
I found two different cables, 6 pin to 4 pin and 4 pin to 4 pin. For the 
life of me I cannot find any specification specifying which of these to 
use for the 2450 to the computer. The sales person at Best Buy had the 
foggest idea what I was talking about.

Anyone have any info concerning this.

Truman