600 GBP? or 600 USD, or 600 AUD, etc?
This is the baseline or yardstick spec that I recommend running comparison against for under $1,000 builds.
You can get the following components, which may be a better deal if you already have a Case and Power Supply Unit lying around, or have a greater than $1,000 budget.
GPU: GeForce GTX760 with at least 2GB --- $320
CPU: Intel Core i5 4670K (3.4GHz), --- $250
MOBO: Gigabyte GA-Z87X-UD3H (Z87 Chipset), --- $227
RAM: Kingston HyperX 8GB Kit (2x4GB) 1333MHz/1600MHz DDR3, --- $70
SSD: Samsung 830 or 840 Series 120GB SSD, --- $128
If you have a lower budget (including the case and PSU) then get a lower end GPU than the GTX760, never get anything less than the GTX760 if you plan to play modern 3D Games beyond 2H 2013 though!
Some vendors may charge up to +$25 for one part and charge $25 less for another part (usually the CPU and Graphics Card).
Then just trim those specs back as required until you meet your $600 budget and ask for a 2nd round of reviews.
This way it's your system, not my system ;-)