£500-£700 gaming PC build

[cal93]

I'm interested in building my own gaming rig but I'm not the best with computer components. Also I would like a small case. So I need some help!
Many Thanks!

 

[cal93]

Hey, Mouse, keyboard & monitor I already have but other than that nothing & the budgets in-between I don't mind people aiming for the more expensive

 

[cal93]

And by 'small case' do you mean mATX? Or just a relatively small ATX case?

I don't mind too much just also as its smaller than a normal tower. Its because my room is pretty small.