Welcome to the forums!!!!
That looks like a solid build and everything should work together nicely. I do have a few things you should consider before buying. You didn't list the current parts you will be keeping, but if those work together already, there is no point in changing them unless you choose to upgrade your graphics card or other parts fail.
1. That is a good motherboard from a respected company. That model uses the AMD 8 series chipset, specifically, the 880G. The 880G means that is has an on-board graphics card. If you already have a graphics card better than the low-end Radeon 4250, and you really should for games, then this is a feature you can live without and get a different motherboard, such as the ASRock 870 EXTREME3 AM3 AMD 870
which has most of the features of the Gigabyte you chose, just at a lower price.
2. I usually don't overclock, but I have seen people get the Phenom II X4 955 and 965 (They're identical with different prices and clocks) up to 3.8 GHz. and 4 GHz. depending on cooling.
3. That heatsink somes with thermal paste already pre-applied, the Arctic Silver is unnecessary. I have an older version of that same CPU cooler for an AMD rig I built for my parents a few years back, it's pretty good.
4. DDR3-1333 is considered standard for most AMD motherboards with faster RAM designed for overclockers. You may have to tweak your BIOS settings to get the motherboard to operate at those higher DDR3-1600 speeds. You can get single sticks of DDR3-1333 RAM, such as the G.SKILL Ripjaws Series 4GB 240-Pin DDR3 SDRAM DDR3 1333
. These single 4GB stick RAM kits are handy if you think you might want to maximize the amount of RAM you install. The difference, in terms of performance, between DDR3-1600 and 1333, is very minor.
5. That hard drive should be just fine. There are Western Digital Caviar Black drives that have 500GB if you're really worried. Besides, hard drives had to be shipped to the retail stores so they have been shaken quite well already and they're designed for it.
6. Finally, ensure that the copy of Windows you have isn't OEM/System Builder, that is, unless it is uninstalled. The license for that version of Windows allows it to only be installed on a single computer and it cannot be moved to a new one. There is technically nothing preventing you from doing this, however. Also, make sure it is 64-bit Windows if you want to use 4GB or more of RAM.