Case: 7/10 - Reasonably well designed, if mediocre quality case. Good value, but needs extra fans installed to do well for airflow.
Motherboard: 10/10 - Best value i5 board out there.
CPU: 10/10
RAM: 10/10
HDD: 10/10
GPU: 8/10 - Good value card, but 1GB for an HD4670 is completely unnecessary.
PSU: 10/10
The RAM you've listed latterly is higher-latency, which means it doesn't perform as well.
Unless you intend to overclock, the cooler that comes with the CPU will do fine.
In order to make your PC have wireless internet access, you need to install a wireless adapter. USB ones exist, but they are usually very unreliable. Instead I would recommend something like
http://www.newegg.com/Product/Product.aspx?Item=N82E16839121008
No, Wireless N is a very unreliable standard, I'd stick to G if I were you - unless you transfer large files between PCs on your local network regularly, you will never notice the difference.
