I would look at something like the Hitachi Deskstar 7200 rpm, I have had a couple of these in a software raid in my MacPro running for over a year without issue.
Or the Seagate Barracuda 7200, or Western Digital Caviar Black 7200 should both be worth a look.
I think they are all available as 2TB or 3TB depending on how much you want to spend, a single drive wont give you massive speed but will be fine for a stream or 2 of ProRes HD
best wishes
Neil
http://www.patience.tv