This is the spec of your motherboard. It supports PCI Express x16, so no problem there. So far as the GTX640 that your dad has recommended - it's a good card, better than your present one and will allow you to play at higher frame rates/resolutions. However, to get what you're looking for - including FRAPS recording - I think you may have to spend around twice as much. If you go that route, you may find that you need to upgrade your power supply. Your CPU is pretty good, but may also be a limiting factor.
HTC U12 Plus review: Hands-on