What do you think of build and a few questions

I am currently looking at building a gaming PC for uni next year, and so far this is the build I have come up with.
I would like to state that I am in NZ so using $NZ dollar for my pricing, I am also using PB eletronic and Pricespy to find the cheapest prices.


Build for gaming PC

CPU

Intel Core i7 920 2.66GHz

$468.00

POWER

Corsair CMPSU-850TX 850W

$292.00

CASE
Cooler Master HAF 932 (Black)

$226.00

GRAPHICS

Sapphire Radeon HD5870 HDMI DisplayPort Dual-DVI 1GB

$674.45 + $674.45

=1348

(Waiting for the new Nvidia and Ati cards befor buying graphics however)

HARDRIVE

2x WD CB 32MB 1TB

= $284

DVD RW

Asus DRW- 24B1LT

$85.00

RAM

Corsair XMS3 Twin3x ddr3 pc12800/1600MHz CL9 3z2GB

$260.00

MOTHERBOARD

Asus P6T Deluxe

$493.00

OP

Win 7 Proffesional 64Bit

$234.00

KEYBOARD

Microsoft Sidewinder x6 keyboard

$111.00

WIRELESS NETWORK

D- Link DWA - 140

$104.00


All together =$3905NZ

Firstly I wana know what you guys think and if theres anything there that needs to be changed.
I also want to know if the PSU of 850 watts is suffiecient for the build
and can someobdy please tell me what fans and cooling i should use or if the stock is fine. Not interested in OC at this stage


also any extra information you can add
First time building
cheers