I'm moving this to
General Hardware which is the normal location for build request threads. Also,
answers to these questions can help us... help you.
A few quick thoughts about the components...
No need for that expensive of a motherboard (Asus Sabertooth Z87). Boards like that are made for overclocking, and you don't have a K series overclockable CPU listed. Also, consider micro ATX, because an ATX tower with one graphics card, one HDD and one SSD is just a big empty box.
Yes the CPU cooler listed (Zalman 9900MAX) will work. However, it isn't the best choice of a cooler though it looks really "cool." There are coolers much cheaper that perform just as well, or coolers just as expensive which perform better. Then again, no overclocking means no need for an aftermarket cooler.
Not sure he needs 16GB of RAM even when multiboxing 2 instances of WoW. Also, no need for expensive RAM either. I see 16GB kits for $45 cheaper. Only reason I would specifically look for the super low profile low voltage stuff is if I were doing a really small ITX rig.
You can usually get a 1TB WD Caviar Blue for around the same price of a 1TB Green. The Green can be irritating because it will always spin down after a few minutes.
The case is kind of chintzy. Maybe saving money on the CPU cooler and motherboard can free up budget for a slightly better case? A Fractal Design Define Mini would be a nice mATX case for quiet. If he wants something cheaper, there are any number of $40-60 mATX cases which will work reasonably well, like the Rosewill LINE-M or RANGER-M, or the Fractal Design Core 1000.
Will the guy be watching Blu-Ray movies? If so, he will need software, which can be pretty expensive. The drives typically does not come with such software.
No need for $80 worth of four 120mm aftermarket fans. You get "quiet" by lowering RPM. You can do that with any fan. The case uses one front and one rear fan, plus two side panel fans. Not very optimal for airflow, IMO. If you wanted better airflow, a different case will do a better job than sticking $80 worth of fans into a $40 case. If you want "quiet" you can use the $120 for a known quiet case, like a Fractal Design Define series.
PSU is okay. Your CPU and GPU choice will only need a 450W PSU so anything over that is overkill. Just make sure it is decent quality and has the two PCIe power plugs needed for the graphics card. Corsair's Builder Series PSUs are not known for being quiet. You can get a Rosewill Capstone 450W for around $60. It is known to be good quality and quiet, plus is 80Plus Gold.