ditzy is right... 
why don't buy an internal drive and an separate external case with
firewire(if you have that inteface on your comp) or/and usb
interface?
In this way, it's still an external drive but most importantly it's
a lot cheaper and the performance is better as low demand for
external drives caused vendors to develop better internal
drives.
You can ask for assistance from ppl at sim lim.
