I put a WD Scorpio Black 320GB SATAII 16MB Cache in my 40gb fat, never had any issues with it, the faster rpm does only give a minimal performance increase but the 16mb cache was the reason why I went with a 7200.
I'd recommend getting a 500gb tbh, you pay a little more but you can be sure you won't be running out of space unless you go daft and store hundreds of movies.








