What size PSU would I need for this setup?

[hypochondriac]

As the title says, what wattage of PSU will I need. And can you reccomend me one?

Also are there any major errors in my choice of setup, I need a PSU still and a case but im not worried about how good the case is.
I got a budget of £500 so I have a little more room for spending if theres anything I can improve

 

[hypochondriac]

Ok its looking a lot better now. Should I go for a corsair psu, i've heard theyre good.

Problem is it brings me over the £500 budget