Basically, if you trust the thread, all graphics cards are compatible with any motherboard as long as you have the slots to support it. According to your link it your motherboard is well equipped to handle just about any type of modern graphics card out there. So the only question is what are you doing with your computer.
Usually, but not always, people who are building their own computers are playing games or doing some 3D rendering. So if your interested in doing that get a card with at least 512mb to 1gb of on board ram, this will allow you to run most games at a comfortable fps. As for ram 4GB DDR2 is more than sufficient to do just about anything...I would imagine that 4GB DDR3 would be plenty
Hopefully anything I said wasn't redundant or too generic. But enjoy your computer; wish I had had the foresight to build my own tower!