P II 955 BE and cheaper HD 4870 (If that 22" that you have has a resolution lower than 1920X1200, then even a single HD 4870 can handle that resolution) and save money for HD 58xx series...
If you can hold your purchase for a month, then you can get this CPU and GPU for nearly the same price - X3 720( or anything better if you save some more cash) + HD 5850
If you can hold your purchase for a month, then you can get this CPU and GPU for nearly the same price - X3 720( or anything better if you save some more cash) + HD 5850
I have a 4870 1GB and it holds fine on my monitor (1920x1080)