My first Apple is being delivered next week, a new retina iMac with 1 tb fusion drive. My current PC setup has a number of additional back up storage - a buffalo duo NAS, an additional internal hard drive and an external hard drive too. I need to make sure the new iMac is similarly backed up. So some questions that may seem obvious to users here but as I'm new to Apple I want to get it right straight away. Will I still be able to use the NAS and if so will I still be able to use it for a windows laptop too? I need a USB drive to dedicate to the iMac. I'm wondering whether it's best to get one with a separate power supply to take the load off the iMac or does separate power not really matter? Any suggestions would be appreciated. I'm currently looking at the Seagate STBV2000200 2TB. Would that be ok? Sadly I can't afford the time capsule, I've blown most of the budget on the iMac itself. Cheers in advance.