Gaming on a Kaveri 7850K?

So this is my first gaming pc, and I just want to play minecraft, chivalry, team fortress 2, maybe BF3 if this permits but I was wondering if I could later on get a GPU and have a performance increase? If so, which one would be good to increase performance and not bottleneck. I don't really mind the graphics, I will be playing in 720p and on low to medium settings. I'm not picky, so with the 7850K satisfy me?