I just lost all my data on my pc laptop. I've been planning to get a mbp15 for the longest time, but I learned a hard lesson about backing up my data. I plan to use time machine to backup all my data and was wondering which harddrive is the best? 1. How much space do I need? 250gb, 500gb, 1tb? 2. Should I get hhd or ssd? 3. I am planning to get two mbps (one for me and one for my wife). Should I buy 2 harddrives for backups or can we use one harddrive and split it between the two of us? 4. What is this RAID 0 and RAID 1 I keep reading about? Is it something that I should consider? My wife and I are planning to use these laptops for basic work (e.g. word processing, powerpoint, excel, web browsing, keeping photos and videos, watching youtube videos, and checking email.) We don't use any super powerful applications like photoshop or final cut pro. Thanks. Any advice is appreciated.