A 512mb videocard is pointless…actual memory size doesn’t matter as much as raw processing power, so just make sure you get whatever the newest GPU is (nvidia 7 series???), a high clockspeed and alot of pipelines.
Buying a soundcard is stupid unless you want surround sound, or something like that. 2gb of ram is also kind of overkill…
If you’re going to be playing games, don’t buy one large HDD. Buy one small fast HDD for games, then another large one for storage. Get a WDRaptor, and install all your games onto it. They have like 10k RPM, so loading times would be way faster. Then buy a slow large drive to put your anime and movies onto, since disk speed doesn’t really matter with those.
Also make sure you read carefully into compatibility issues with your components. Read reviews at a place that tests items real world, like HardOCP, of everything you’re going to buy to make sure it will all work together. ie: your motherboard supports the clock speed of your ram, the bridges on your motherboard play nice with your videocard, etc.