Hi, I got an iMac with a 1 TB internal HD (Mac OS X 10.6.8, 2.93 GHz Intel Core i7, 4 GB 1333 MHz DDR3). We are going to scan vintage slides into digital scans to keep for posterity. I don't want to use the iMac internal HD for that and am planning to get an external 1 TB HD specifically for this project to store all the scans. I am also planning to get an additional HD for set up Time Machine for backing up both the iMac and the external HD. I currently own an Airport Extreme Base Station. Hence. I was planning to hook up the Time Machine HD to it in the USB drive and use it as a network HD. 1) Is it possible to configure Time Machine to back up both the iMac and the external HD under this configuration? 2) Are there any recommendations about what kinds of HDs to get for Time Machine and to store large number of image files? My thought is to get the following: * a fast 1 TB HD with a FireWire connection to the iMac (800 Mb/sec) for the image storage. * a 2 TB RAID mirror setup (4 TB total) with a USB connection to the Airport Extreme Base Station for Time Machine. Other considerations include: * portability of the image HD is a plus, but not required * cost is not an issue, but keep it real ;-) Any suggestions are welcome. Thanks!