That's compatible, assuming you have a decent power supply. It's not a particularly powerful card for gaming though if that's your aim.
Also, don't buy the 4GB version, it's more expensive than the 1GB or 2GB variants and it's no faster. There are several different variants of the GT 640, the one with GDDR5 memory is faster than the models using GDDR3. There's also a GT 640 v2 card which should be faster than the original variant due to higher clock speeds and a new core.
Edit: looking through what's available on your link, the GTX 650 and 7770 are available for a similar price and perform better, or there are standard GT 640s available a fair bit cheaper than the 4GB GT 640.