What's the point? USB/Firewire bottlenecks the drive to the extent that if you used an SATA drive in an enclosure as opposed to an IDE one, you'd just be wasting money since the speeds would be about the same.
But now my point is all the ata drives are more expensive than the sata. Why would I buy ata for more money? When I am done with it I can use it in my computer if I want.