Someone has already said, but booting from a firewire device would require BIOS support, and then the device would likely have to be integrated into the motherboard, or a definite standard set up (which I'm not aware of one, but then I don't know much about firewire).
To get Win2k to install onto a firewire storage device, it would have to have specific drivers to support the firewire card and storage device that are specifically designed for setup mode (to confirm this, there should be a 'txtsetup.oem' file in the driver packs). AFAIK, but not sure, but I think Windows firewire support isn't 100%. It doesn't support everything conceivable. What I mean by that is, it doesn't support certain concepts, like say booting off a firewire device, or for wild example, a firewire camera. Drivers can obviously fix it not natively supporting a certain device, but it needs to support the basic method. For example, for NT4 to support AGP devices, one needs to install Service Pack 3 or above first, otherwise you're totally out of luck. No driver would fix that (unless it was a horrible hack).
Try
http://support.microsoft.com/ searches.
People keep talking about Win98 in this thread, I'm not sure why, I kind of ignored the rest of their post :-) But Win98 is very unlikely to support your plan. Win2k is unlikely to IMO as well, but less unlikely than 98, as 98 has been forsaken by MS and the only people likely to support it are the hardware manufacturers.
