Need a new budget psu for a intel core 2 duo e8200 and radeon hd7770

Hi there i am new to tek syndicate forums and building pc's but im wondering what wattage i will need for a core 2 duo e8200 and a hd7770 asus direct cu edition graphics card?

I already have a 500w psu thats powering the e8200 and a old nvidia geforce 8600gts, but can i get a new power supply that is under £60 600-700w (i live in the uk)thats good quality and cheap as im on a budget...

Thanks for taking time to read,

That core 2 is going bottlenceck that gpu like cray cray. Don't us it, Buy an athlon ii x4 or a phenom ii x4 965 black. If you must go Intel buy an Ivybridge Pentium. Anyone else will tell you the same thing. You wont need more than 500W so stick with what you have. But please buy a new cpu or else your going to be a be very dissapointed. I had a core 2 quad that couldn't handle a 550Ti. Anyone else agree?