Not sure about the HDD's, but you will also need a keyboard and most likely a mouse as well to play.
Get the latest expansions and start playing, I've come to appreciate the game, even though it's unfortunately very slow and doesn't really start getting interesting until you reach Rank 3, around level 18-20. And even then, it gets TRULY interesting only first when you can get Advanced Jobs at around Level 30.
I used to play, but not anymore. Will start again once I get my new computer. I play in Fenrir and in Carbuncle. Leviathan isn't a very good server. Carbuncle is great.
I have a Mithra in Fenrir. It's a Warrior at Level 15 or 16. I love how you can keep toying around with classes a lot. What I really want is to play with Taru-Taru, I love them!
Tell you what. If you ever decide to start playing in the future, I'll try helping out if I can! Or start playing with you, or something
One thing FFXI has that is a BIG plus is really great music. I love listening to overworld themes like Saruta Baruta and Ronfaure.