I'd up the GPU to a 660Ti for gaming. The CPU is relatively slow, but it has been used as the basis of a gaming system before (with a good GPU, that's essential to make it viable). I'm guessing that's an SSD if it's 100GB...you won't be able to get a huge number of games on it, but you can also buy a spindle-based drive for relatively cheap later on.
Make sure you get a good PSU...don't get a cheap one, it can take out your whole system. Also, Windows 8? I'd respectfully suggest Windows 7 for the time being...it can be upgraded to W8 later if it turns out to be good, and W7 is fine for gaming anyway.