Advice on system build

[Kontraption]

Hi,

Here's my outline. I've chosen most parts and wanted some critique

What is your budget?

$800

What is your resolution?

1920x1080

What are you using it for?

Mostly gaming.

What is your upgrade cycle?

1-2years

When do you plan on building it?

next 2 or 3 weeks

Do you plan on overclocking?

No

Do you need an Operating System?

No

Do you plan to add a second GPU for SLI or Crossfire?

No

Where are you buying your parts from?

Australia, http://www.pccasegear.com

---------------------------------------------------------

ASRock H77-PRO4-MVP Motherboard
Intel Core i5 3470
Sapphire Radeon HD7870 2GB GHZ

G.Skill Ripjaws F3-12800CL9D-4GBRL (2x2G) DDR3
Antec VP550P 550W Power Supply

TP-Link TL-WN751ND Wireless PCI Adapter
Western Digital WD Blue 500GB WD5000AAKX
BitFenix Merc Alpha Mid Tower Case

I have monitor/keyboard/mouse/optical drive

Thanks in advance for any advice

 

[malbluff]

All looks OK. 4GB of ram is adequate for gaming, but RAM is so cheap, now, you just as well put in 2x4GB. Haven't had anything to do with that case, so I'm ASSUMING it's OK. I do note no optical drive?