First thing I'd recommend you to do is to buy everything from one shop. I use Novatech myself, great customer service. It gets confusing buying from different shops, especially when/if you have to send something back and you can't remember for the life of you where it's from. That's one of the reasons why I dislike this 'PC Part Picker' thing. :/
Anyway, as for your build.
i5 3570K: Awesome, don't change.
Z77 Extreme4: Get the Gigabyte GA-Z77X-D3H instead, much better board.
RAM: Great, don't change.
Graphics: Good choice, maybe try and get a Sapphire or MSI or ASUS card if they're not much more expensive, otherwise PowerColor will do.
PSU: Great.
Case: OK, but the Carbide 300R from Corsair is newer and has better cable management features. May even be cheaper too.
Monitor: Yeah looks OK.
DVD Drive: Yeah, it's OK. I'd get LG or Samsung or Sony though.
HDD: Yeah OK, go for 1TB though, maybe one of the Seagate Barracuda 7200RPM 1TB disks. Faster and bigger.
Extra Fan: I don't see why you need it.
Look for those parts on Novatech or Overclockers and buy from there rather than about 50 different stores.
