I don't think there's really a -be all end all- hard drive. I did pretty well five boxing on one 7200RPM hard drive. It could have been better, I'm going to try a RAID 0 setup in the future.

Referring to sound - I have no clue, I always used a USB headset for sound.

As far as fans, I did pretty well on stock cooling for my CPU. If you're not overclocking or anything like that, you shouldn't have too much trouble with stock cooling.

Please note: I have limited experience with building computers. Take my advice with a grain of salt. Maybe two or three grains.