That motherboard also has an AGP port. AGP is better than standard PCI, so I would go for that. The combined cost for those components are $149, $129 after rebates. I chose the Radeon 4650 because is it powerful and is one of the few cards for AGP with specifications and reviews that are decent. The Radeon 4650 is a mainstream card from last generation, so it isn't cutting edge or high performance. To run that graphics card, you need a 400W PSU. On a new system, I usually suggest going for a power supply that is 100W over the recommended wattage for the graphics card. However, due to budget considerations, I used 50W over for this build. If you want to save money with the power supply, I guess we could go for one from a less well-known brand, but you would still probably be above the $100 mark. If you want to do that, you can get the Antec Basiq BP500U 500W
. I've had problems with Antec, but they aren't bad. You could also get the SAPPHIRE 100258L Radeon HD 3650 512MB 128-bit GDDR2 AGP 4X/8X HDCP Ready Video Card.
That card is from the Radeon 3 series (Radeon 5 is the most recent generation), it is older and not as powerful as the 4650. But it does cost the same as the 4650 after rebates. It's also possible that your CPU cannot handle the processing of those games or you need more RAM. What is your CPU model and speed? How much RAM do you have?