Bought two external drives, which one to keep?

Hi,



Over the last few months a lot of you have given me a lot of information about external hard drives and I am very grateful. I was still vacillating all these months and during that time larger drives started appearing.



Today I finally actually ordered. I have ordered two drives, both at Costco. One is the 1TB Ethernet drive and the other is the 1TB USB/FW400/FW800 triple interface drive. The Ethernet drive does not have USB or FW, only Ethernet. BTW, both drives are the WD My Book family of drives.



I have one last question and based on the responses, one of the drives shall be returned:



I have a first generation Core Duo MacBook that only has FW400 and USB 2.0 and Ethernet of course.



I would like to keep my iTunes library, my iPhoto library and rip all my DVDs on the external drive and remove them from my laptop. I shall stream iTunes from my external drive to my laptop.



This being the requirement, would it be better to use the Ethernet drive or the USB/FW400/800 drive? Please remember that I do not have FW800 on my laptop.



Would the Ethernet on my old Macbook be faster than USB or FW?



I do not have an Airport extreme, but I do have an old Airport Express. Can I connect the USB drive to the Airport express or does that work only on an airport Extreme?



Another question:



Considering Leopard will soon be out, I thought of using this drive for Time Machine. That being the second requirement, would you now advice the Ethernet drive or the USB drive (since the USB drive will not be permanently connected to my laptop)



Thanks and cheers