PSU you should get to make sure it has all the correct connectors for that D945GCCRG1 motherboard and has one PCI-E 6pin.
Corsair CX 430W ATX Power Supply (CMPSU-430CXUK)
http://www.overclockers.co.uk/showproduct.php?prodid=CA-033-CS
Graphics card with one PCI-E power requirement.
**B Grade** XFX ATI Radeon HD 5750 XXX 1024MB GDDR5 PCI-Express Graphics Card ***OcUK Exclusive***
http://www.overclockers.co.uk/showproduct.php?prodid=BG-077-XF&groupid=595&catid=683&subcat=
Total price for graphics card and PSU = £112.82
Buying anything else would be a waste of money on that system. E4700 will be fine just don't expect miracles, it will play most of the games fine... Also what resolution monitor have you got there ?