Great build, but the motherboard should be phased at least 4+1 with an energy waisting Phenom. Get the GA-78LMT-USB3. It costs a few bucks more but is phased 4+1 and has heatsinked vrms. The Phenom comes with a fan so you won't need one. You only need third party cooling if you plan on overclocking, which you can't do with such a motherboard.
The build I put together has an FX-6300, a 7870XT, a decent aftermarket cooler (212 Evo) which should let you overclock the CPU up to 4.2-4.3 GHz, as well as a copy of Windows.
You don't need a CPU cooler, but it would be advantageous over the stock cooler. It would be much quieter, and keep your CPU much cooler than the stock cooler would. If you decide to buy one later on, all you'll have to do is un-mount the stock cooler, clean off the thermal paste with some isopropyl acohol 99% and a coffee filter (not a tissue, as they tend to leave fibers on the CPU), re-apply the new thermal paste for the newer heatsink and mount it onto your CPU.
As for a case, you might want to check out the Fractal Design Arc Midi R2. It's a very nice mid-tower case with great airflow, some nice looking aesthetics, and a nice large window.
I would drop down to 1600MHz memory to shave off some dollars there, RAM speed isn't that important. And I'd get an FX-4300 instead.. a bit less power hungry and performance is better for the most part
The 955 being ahead just barely with multithreaded and with flash video creation.
EVGA GTX 650 Ti BOOST 2GB is the exact same price as that XFX 7850 1GB, so I'd go with that personally. That extra VRAM is really going to help w/ games coming out as I believe the texture details on BF3 eat up more than 1GB if on ultra.
clock speed is how many times a second the gpu "does a calculation"
i guess you could think of it like an engine in a car. the faster the rpm, the fast you go (on 1 gear)
this being said the 1.06Ghz one will be faster out of the box. But will most likely have less over clocking headroom. meaning it will hit it's max sooner.
If you're not going to overclock get the one faster out of the box.