I'm planning to buy the 500GB 7200RPM seagate HD for my MBP and take the current HD in the MBP and use it as an external HD. Therefore, I'd obviously have to get a external enclosure. However, I want FW400/800 for speed...but the prices for FW400/800 enclosures is $80.00 at minimum (from what I can find). Is there any difference between having a FW port and a USB 2.0 other than speed? Is it possible to boot from the external HD if it has FW? Thanks in advance!