Gaming prebuild any good?

I'm looking for a gaming computer but I have no clue on all the jargon, which is why building a computer is not an option since I wouldn't know where to start.
I've got a budget of £900 and I'm not really looking for something super high tech just something that will work smoothly.



I'm looking at the chillblast fusion striker at the moment (http://www.chillblast.com/Chillblast-Fusion-Striker.htm...):

Cooler Master Elite 430 Case
Intel Core i5 2500K Processor 3.30 GHz (No Overclocking)
Arctic Cooling Freezer 7 Pro Rev 2 CPU Cooler
Generic thermal paste
Asus P8Z68-V LE Motherboard
8GB PC3-10666 1333MHz DDR3 Memory (2 x 4GB sticks)
Chillblast NVIDIA GeForce GTX 560Ti 1024MB Graphics Card
1000GB 7200RPM Hard Disk - 6Gbps
24x SATA DVD-RW Drive
Corsair Ultra Low Noise 600W PSU
Onboard High Definition Audio
Windows 7 Home Premium 64 bit
Standard Chillblast Cable Management
24" Asus VS247H Widescreen LED Monitor
Generic Wired Keyboard and Mouse
Generic 2.0 Basic Speakers


(I've made a couple of changes to the original but any further advice would be great)