There is no need for a £1000 unless you want to build a monster like me.
Good gaming computer will cost you around £550 ~ £750
And as I previously said, here is the pre-build PCs that you still can configure: https://www.cyberpowersystem.co.uk/c...y/configurator
But, here is your £1000 PC: http://pcpartpicker.com/p/pdMqf7