I need some new HDD's (or maby only one?).

I have approximatly 210$, and was looking at the F1's (640's and 320's).

First i was off buying 2x640, but i dont know if its a bit overkill for me, i have maneged with a 200GB Seagate untill now, i admit i have had some space issues but nothing i couldent handel with a few deletes.

I have a lot of FLAC and ALAC music on my harddrive and some movies too.

I want a swift storage system for both storage and OS.

Shold i go with one 640, 2x320, 2x640 or maby 2x320 and another one if i need more space?

And a little bonus question, are there some good cheap raid contolres out there, or is the onboard good enough?