For an extra $60 you could get the Athlon64 3500 socket 939 cpu. That is a pretty good processor. You may want to consider the upgrade.
As for that case I suggested, the part about it that is good is that it comes with a very reliable power supply. When people are putting together budget systems like you are now, the mistake a lot of people make is getting cheap power supplies. Trust me when I say, you don't want to go that route.
Most PSUs that come with cases are complete trash, and actually quite dangerous to the system unless it is from a company such as Antec. If you choose to get a different case, it is probably best to get one without a power supply, and then buy the power supply separately. For the specs of the system I have put together above, you only need a 350w psu or so. Look at companies like FSP (fortron), enermax, antec etc., and make sure you have at least 24amps on the 12v rail of the PSU you do end up getting.