What PSU do i get?

[Yucca]

I have a £800 budget and am going to buy a cheapo case (no point spending loads just to look good) and get a nice good psu. I am going to buy somthing like... dual core amd chip, 2 gig ram, x800xt pe, 300 hd ect ect

So what PSU should i go for. I am prepared to spend about £60 on a PSU. Which do you all recommend and why?

 

[Yucca]

Whats the difference between a modular and normal?

And dno i really need a 500w + PSU or will a good 400w+ do the job just fine?