Please Help Building First PC

Hi there, thank you so much for taking the time to read my thread

I am building a PC with a friend and need some assistance if you can give me your time:

PARTS

CPU
Core i5 ---> I do not know which model is best, bearing in mind I am on a tight budget so I found that Core i5 750 2.66mhz for £170 but that is a bit too much, but if it is markedly better than the alternative I do not mind, Thoughts on this?

GPU
ATI 5770 1GB £130 -----> Heard this is the best value for money card

MOBO
Gigabyte Socket 1156 ATX ~£80
http://www.ebuyer.com/product/189292

RAM
Corsair 4GB DDR3 @ 1600mhz ~£90
http://www.ebuyer.com/product/173122

Case + PSU Combo
Coolermaster Elite 334 case + 460W PSU ~£60
http://www.ebuyer.com/product/192207
Found this special deal at Ebuyer for both
Would 460W of Coolermaster be enough to power this? if not, what is a good one to get, i have a corsair 550W on my other pc but its too expensive for the range I set out for this rig

Hard Drive:
Samsung HD103SJ 1TB HDD ~£50
http://www.ebuyer.com/product/173804

ATM my total comes to ~£580 that is a bit steep for me as I would like to keep it at the 500 mark

Please take a look at this list and let me know if any alternative would be better and the cheaper the better!!

Thank you so much


Best Regards

OSiRiS