I've checked your motherboard, and it has the necessary PCIe x16 slot, so you can fit any PCIe graphics card as long as your case has sufficient room for it (it looks big enough).
I would recommend buying an AMD HD 6450, like this one:-
click here could save a few more £ and get a 5450, but I would go for the more recent 6450 myself. These cards require very little power to run, and you should be alright. The card I linked to has a passive heatsink (rather than a cooling fan) and is silent.