Follow on djspinnet's advice n you'll be able to boot yr whole hdd externally even with usb. If you still want Windows then use Parellels, as I have not tried boot camp with an external drive.

The important thing is to format the partition to GUID if Intel Mac, during cloning. Also note that u can boot via usb, there are very few, if none, sata enclosure with firewire in town. You wil have to buy Lacie's but warranty expires once u remove the hdd from enclosure or import them yrself.

For the physical installation, again take djspinnet's advice n send it to an authorised reseller ie machines becos 1)they know how to do it 2)the hdd swap record is updated 3)u may not have the tools

Hope this helps and it's real easy, Good Luck!