My first ever build. Gaming PC. Sound good?

[Queefism]

Processor- Intel i5 2500k
Motherboard- ASRock Z68 Extreme3 Gen3
Harddrive- Seagate Barracuda 7200rpm 1tb
GPU- Radeon 7850 2G
PSU- Antec High Current Gamer 520W
RAM- G-Skill Ripjaws DDR3 1600MHz 2x4G
Chassis- Antec Three Hundred Case
Optical Drive- Asus DRW-24B3ST
Monitor- Viewsonic VA2248mm-LED
Windows 7 Home Premium 64 Bit

Setting me back close to $1200 US.

I'm most concerned about whether all of these parts work together. Any advice thrown my way in terms of improving/not spending unnecessary money shall be taken on board.

 

[ferguj1]

Dont have the time at the moment to look into much but I am not a fan of seagate drives. Would much rather invest in a western digital.

 

[Omnius]

It is all compatible. However Personally, I'd go for two HD6850s in crossfire. The price will be marginally higher, however the performance would be much much higher. I have seen HD 6850s going for £85 brand new. However this might mean that you would want to get a powerful PSU.
If you decide on getting a single GPU, I still would not recommend the HD7850, the HD6950 is about the same price, and yet again offers high performance. The 7*** range seem not worth the money unless you are going for really, really high end gaming.
I have even seen Nvidia 570's go for sub £200 prices. These even out perform the HD 6950s, however they are 1.3GB of VRAM instead of the 2GB.