I've decided to purchase my first Mac, and have decided on a used 800mhz or 1ghz iMac with the Superdrive. The iMac will be used primarily for the iDVD, iPhoto, and iMovie applications, however it will also be used by a five year old on a regular basis. Questions: I'm aware that the 800mhz and 1ghz iMacs have different hard drive speeds; bus speeds; memory; and video cards, therefore am I better off shopping for a 1ghz, or will the 800mhz be sufficient for my described usage? Is it worth purchasing Apple Care for used iMacs (i.e., are iMacs dependable and are repairs expensive?) Finally, are the flat panel LCDs fragile (a five year old will be using the iMac)? Is there any protective covering that can / should be used with the LCD? Thank you.