I have been wanting to get an external hard drive to back up data for both my desktop and my wife's laptop, but they're just so doggone expensive. A friend told me that I can buy an internal hard drive with some sort of a case, get a PCI card with an external SATA hookup, and I'm good. I figure this would be cheaper (and a smaller profile to boot). I've already got Acronis True Image so I don't need any backup software. What do I need to look for when I'm shopping for stuff? I'm looking for at least 300 GB