If i were you, Id buy an i5-2500K then spend more on the GPU. Thats alot for a mobo, although it has good features, just get a z77 if you plan on OCing. A great GPU is the 7850 btw. Id also look at the CoolerMaster HAF 912 (case i always recommend xD)
As for the monitor, all depends on how big you want it.
Windows 7 Home Premium 64bit generally costs $100.
Thanks for the reply. I think I'll go with the 2500k for my processor, because I looked it up and realised there is almost no difference from the 2600k, but I was just wondering, how many years will I get good performance from it? One of the main reasons I'm allowed to build my pc is because I told my parents it would last about 3 years, so that's why I was planning on the i7.
I think I'll stick with the motherboard only because of all the features I get from it.
For the GPU, does the 7850 support DX11?
I'll have a look at the CoolerMaster Case, and I'm pretty sure I've read about it before.
Lastly, I thought you couldn't buy Windows 64bit separately?