This really should be in the Homebuilt Systems section.
CPU: The Phenon II X4 965 isn't worth it IMO - Phenom II X4 965 is essentially the same as the 955, but with the CPU multiplier is upped to x17, instead of the 955's x16. You can easily just up the multiplier yourself to x17, and I wouldn't pay $20 for someone to o/c my computer 200MHz.
As for the mobo and case, what is your budget? Do you need/want CrossFireX support? Do you need/want SATA III/ USB 3.0?
Two good motherboards which have all of the options above are the ASUS M4A89GTD PRO/USB3 and the Gigabyte GA-890GPA-UD3H.
If you want a flagship board, with all the pro overclocking features, get the ASUS Crosshair III Formula or the MSI 790FX-GD70.
If you can wait however, and do want a flagship board with overclocking features, I suggest waiting for the ASUS Crosshair IV Formula or the MSI 890FX-GD70.
As for the case - I wouldn't know really.
I'm sorry for posting this in the wrong section.(my 2nd day here) My budget for the case is around $100, for the MB around $250.
May I ask when the new Crosshair 4 is to be released?
According to techPowerUp!, the Crosshair IV Formula will be released in late April, along with Phenom II X6. The ASUS Crosshair III Formula currently costs $199.99 on Newegg, I'm supposing the IV will also cost around the same, probably a bit more, so should be within your budget, if you can wait. Otherwise get the Crosshair III Formula or 790FX-GD70, or the other boards I suggested above if you want SATA III/USB 3.0.
A really nice case for $100 is the Cooler Master CM 690 II Advanced. If you like red though, then, the Cooler Master HAF 922 is a pretty good case as well.