Hello, I just bought a used 2008 20" 2.4 ghz iMac. I haven't used macs in a long time. I would like to make and image of the hard drive as it is right now, so that I can just roll it back to its current state. I am looking at firewire 800 external hard drives to buy one to use with this machine. Does anyone have any advice on drives and the best way to make an image of the drive?