dangtx, if you think the PS04B is less "kiddy" than the Centurion 590 in terms of looks, then you simply have no taste. As far as design, the 590 has a similar layout but with more space for fans and a more open front grill (along with air filters). It is also a much better-built case. I know you love the PS04B, but it's a cheap, mediocre case, and that's that. Its only advantage is price, but it can't compete with better cases like the Centurion 590, 690, 690 II, HAF 912, etc. when it comes to build quality. End of debate.
PowerSauce, I recommend this kit of RAM:
http://www.ncix.com/products/index.p...r&promoid=1015
I don't suggest a 500GB HD, especially not a 5400RPM model. If you're looking for something cheap, go with a 640GB Western Digital Caviar Black, or if you want more storage and the best performance, look for a 1TB Samsung F3 (Newegg sells them), or a 1TB Caviar Black.
Between those two combos, the i5 will give you the best performance and longevity, though the AMD combo would be better bang for the buck. I personally believe in getting the best-performing components your budget will allow, so I would go with the i5.