Gaming PC for a Noob, help needed please

Hi,
I'm a noob at building my own pc, i'm a gamer in ps3, so im trying to switch to pc so i need help, any advice would be EXTREMELY helpful, since i dont know anything about this stuff.
the parts i used is mostly in ratings and reviews, however i don't know if they match
my budget is around $1,000 us dlls.

pproximate Purchase Date:
From this date and the end of this year (2012)

Budget Range:
About 100$, but i'm not locked on the price. But somewhere near that would be great.

System Usage from Most to Least Important:
Exclusive for gaming.

Parts Not Required:
Mouse, keyboard, monitor, and OS, since my office have spare licenses.

Preferred Website(s) for Parts:
I don't have any preferred website, the easiest one would be better (amazon, newegg, etc...)

Country:
Mexico, but i plan to ship to US since i have a house there as well...

Parts Preferences:
None.

Overclocking:
Yes, later on. Just for fun.

SLI or Crossfire:
Yes, later on. i want to keep adding stuff later.


Additional Comments:
FPS gamer, so fluidity/graphics is what I'm looking for, that's why im getting out of PS3 world.

This is my tentative setup:

PCPartPicker part list: Intel Core i5-2500K, XFX Radeon HD 7950, Cooler Master HAF 912 - System Build - PCPartPicker
Price breakdown by merchant: Intel Core i5-2500K, XFX Radeon HD 7950, Cooler Master HAF 912 - System Build - Price Breakdown By Merchant - PCPartPicker
Benchmarks: Intel Core i5-2500K, XFX Radeon HD 7950, Cooler Master HAF 912 - System Build - Benchmarks - PCPartPicker

CPU: Intel Core i5-2500K 3.3GHz Quad-Core Processor ($199.99 @ Newegg)
CPU Cooler: Cooler Master Hyper 212 EVO 82.9 CFM Sleeve Bearing CPU Cooler ($32.30 @ NCIX US)
Motherboard: Gigabyte GA-Z77X-UD5H ATX LGA1155 Motherboard ($181.98 @ Amazon)
Memory: G.Skill Ripjaws X Series 8GB (2 x 4GB) DDR3-1600 Memory ($56.99 @ Newegg)
Storage: Western Digital Caviar Blue 320GB 3.5" 7200RPM Internal Hard Drive ($69.00 @ B&H)
Video Card: XFX Radeon HD 7950 3GB Video Card ($337.86 @ Newegg)
Case: Cooler Master HAF 912 ATX Mid Tower Case ($49.49 @ SuperBiiz)
Power Supply: SeaSonic 620W 80 PLUS Bronze Certified ATX12V / EPS12V Power Supply ($83.99 @ SuperBiiz)
Optical Drive: Samsung SH-222BB/BEBE DVD/CD Writer ($14.99 @ Newegg)
Total: $1026.59
(Prices include shipping and discounts when available.)



Thank you!!