After looking at its spec, the official EW162I only comes with USB2.0 connection and no firewire. In case you don't know, the EW162I is the external version of DW1620, which was already phased out. The replacement is DW1640 (external = EW164B) which is almost extinct and most likely discontinued as well. The newer model is DW1650 or DW1655 but there is no external version at the moment.
A good suggestion by brokenbuga, ie to make your own external drive from an internal one. In the US currently you can get the DW1655 for less than $50 from newegg and another $30 for the enclosure with a flashable Prolific PL-3507 such as this silver or black one.