$2000 Gaming build (Australia)- First time builder

Hi there, was hoping to get some advice on this build before I go ahead and buy incase I'm doing something stupid. I haven't built a PC before (family uses macs) so i'm very excited ^^. I've read this site a lot to help me educate myself and then pick the best parts so thank you.

Approximate Purchase Date: Today or tomorrow hopefully!

Budget Range: ~$2000 AUD, then will spend about $500 of peripherals

System Usage from Most to Least Important: Gaming, watching movies, study, web surfing

Parts Not Required: I require all parts

Preferred Website(s) for Parts: pccasegear.com - from what I can gather it's the best Australian site for this

Country: Australia

Parts Preferences: i5 2500K, parts capable of overclocking if I choose to try it out in the future

Overclocking: probably

SLI or Crossfire: Not initially, but maybe in the future if I can afford it... probably not for at least a year.

Monitor Resolution: (e.g.: 1024x768, 1280x1024, 1440x900, 1600x1200, 1680x1050, 1920x1080, 1920x1200)

Additional Comments:
1) I am not opting for a SSD at this stage because they just seem really expensive. I mainly will play sc2 and skyrim so i'm not sure how much it would benefit my anyway..
2) Also, I think that I would be better off with a P67 mobo but pccasegear doesnt seem to stock them :S.
3) I'm a bit concerned about whether I will have sufficient cooling as australia can be quite hot   and the room which the computer will go in does not have air-conditioning  .

Anyway, here is my build:

Lian Li Lancool First Knight USB 3.0 PC-K9 Black $109
(http://www.pccasegear.com/index.php?main_page=product_i...)

Intel Core i5 2500K $229
(http://www.pccasegear.com/index.php?main_page=product_i...)

ASUS P8Z68-V Gen3 Motherboard $199
(http://www.pccasegear.com/index.php?main_page=product_i...)

Seagate Barracuda 1TB ST310000524AS $105
(http://www.pccasegear.com/index.php?main_page=product_i...)

G.Skill Ripjaws F3-128000CL9D-8GBRL 8 GB (2x4GB) DDR3$59
(http://www.pccasegear.com/index.php?main_page=product_i...)

Gigabyte Radeon HD7970 3GB $729
(http://www.pccasegear.com/index.php?main_page=product_i...)

Corsair HX-850 Power Supply $215
(http://www.pccasegear.com/index.php?main_page=product_i...)

LG CH12LS28 12X BD-R Blu-ray DVD Combo Drive $65
(http://www.pccasegear.com/index.php?main_page=product_i...)

CoolerMaster Hyper 212 EVO CPU Cooler $39
(http://www.pccasegear.com/index.php?main_page=product_i...)

ASUS Xonar Essence STX $195
(http://www.pccasegear.com/index.php?main_page=product_i...)


Any comments/ advice will be greatly appreciated. Thanks! Oh, also, I read a throw away comment on another forum about ASUS P8Z68-V Gen3 "not being very good". They didn't explain why or anything- anyone have any insight to whether this is accurate? as it worried me a bit, but not enough to take it out for now. THanks!