I find that onboard sound quality is usually poor, so I always buy a dedicated sound card, and I tend to go for a Sound Blaster with the front panel option also, that takes a 5.25" bay - great for headphones and other connectivity.
Have you already got speakers?
I would recommend more than the minimum fans - several large-diameter fans working slowly are more effective and quieter than one going flat out!
Don't forget a decent CPU cooler as well - Noctua are the best I've come across, but expensive!
At 2x2gb, dual channel is going to be a largely theoretical endeavour, and also is a waste of slots and will be a pain when it comes to putting in more ram because he'll probably end up having to remove and throw away those two chips.
That mobo has 4 RAM sockets, so 2 x 2 can be upgraded to 4 x 2. Best way to go, IMHO. Start with 4, go to 8 if necessary, and get the benefit of the dual-channel.
SD