I would actually just go with jrgong's build, it looks very solid (though his hyperlinks appear to be broken).
Only considerations I would add is that you may be able to spend less on the HDD depending on how much capacity you need, and you also mention being partial to nvidia. In that case, I would suggest something like the GTX 660 for graphics instead of the Radeon.
The Challeneger should be a fine case, but there are a few other options in that price range as well, such as the Antec 300 for $40 and the Zalman Z11 Plus for $50. Just pick the aesthetic that suits you.