DJ how dare you!!! Stealing my budget AMD build suggestions, although in fairness you have saved me spec'ing a rig lol
I will post a link so the OP can compare CPUs i3 vs i5 and AMD.
In short the 965 is on par with an i3 2100. Although in games that want a quadcore the 965 will beat it. Of course an i5 is a better core system but a decent mobo and i5 CPU is gonna eat half your budget up.
I would change DJ's spec slightly. Change the GPU for the 5850 which is on offer and has excellent performance for the price. Also swap the mobo for Gigabytes GA-880GM-UD2H (£58) slightly more expensive but a better mobo with more RAM slots.
What DJ didnt mention is that you can make the 955 a 965 by upping the mulitplier in the bios. You get a £15 more expensive CPU for pressing a couple of buttons.
I would agree with Surveyor about the PSU, I usually make that observation on that bundled case and PSU. Your GFX card may come with a molex adapter but if it doesnt your stuck till you get one. You wont have any issues with that Bequiet psu and has plenty of power for your needs.
Good luck with the build, any problems or questions come back to us
http://www.anandtech.com/bench/Product/289?vs=102