Pick your own case. Also I'd suggest getting cheapest 120/128GB SSD to have OS and most frequently used applications/played games on - any SSD would do a hell of a lot better than a HDD, especially if it's just a single HDD.
This will play much better on the games you mentioned. You definitely want an nvidia gpu for your games.
Drop down to a MSI 660 vs the 660 Ti, fps difference 5-20 depending on the game; Get a much cheaper case with bad cooling, that case is best bang for buck with a 4 fan system, and a 660 to try and fit an SSD; My recommendation is leave as is, and splurge for an SSD now, or at a later date.
I sometimes question people's choices to put higher wattage CX series in the build. Personally, I would only go as high as the CX500. There's a reason why they're so cheap, they are low-end units after all (but people will buy cheap 600/750w units, especially with the corsair name on it.)