Thank you for posting power supply information. You have no clue how much this helps. So many people dont do it.
I would recommend the Radeon HD7770 with your power supply. It does not use alot of power and therefore is perfect for your computer.
Is there something a little cheaper that u can suggest to run games at decent settings ?
That card seems to a bit over 200$ over here atm.
Would a 7750 be a viable option cause there's around a 60$ price difference between 7770 and 7750