you can get win7 a lot cheaper, like about $90 cheaper. and yeah, 16GB of ram is kinda useless, 8 will get the job done. maybe upgrade the gpu with the saved money
You only need 650W power supply maybe 750W if you plan on Xfiring (corsair, seasonic, silverstone,enermax). Save some cash with the watercooling, and get a Cooler Master 212 Evo, and get a 1TB hdd (seagate and western digital are best). Unless you are rendering or video editing using Adobe products, a GTX670 will be slower then a 7970. This also means you dont need 16GB of ram 8GB of crucial is fine. (or gskill, corsiar, kingston, muschkin). I would look into getting windows 8 for 40$ (or 15$ if you are willing to lie a little).
To the above comment. Crucial is good ram, and Windows 7 Home Premium (Which is saying he is using) can have up to 16GB of ram.