looks like you have an old set up. seeing how you are limited by that- a 5670 would be about the best card I think would benefit from what you have and blow the old card out of the water. it should play those games well at that res and you should be able to play most fps well enough........ still running XP ?
BEFORE YOU BUY THIS CARD THOUGH........... WE NEED TO KNOW IF YOUR SYSTEM IS PCI-E OR AGP......... VERY IMPORTANT TO GET THIS RIGHT. .........
if you know what motherboard you have please list it so we can better help you.
okay.the card I listed above should work. as far as fps, it'll be faster and you will get more but don't forget that what else is in your system makes a difference too. you would be cpu limited. every time i upgraded my graphics card when using 939 it always mad a difference.