The FX5200 is an incredibly poor graphics card and will only run the latest games at minimal resolutions with low detail etc.
Revenant the galaxy 6800GT is a good choice simply because it comes fitted with an NV5. The 6800 GPU runs incredibly hot so the NV5 is defiantly the best way to cool it and prevent the temperature inside your case going up a few degrees or so. The card is also powerful enough to keep you entertained for a couple of years at least, although obviously as time moves on it will become lacking in features etc. but the raw processing power of the card should keep it competitive.