for your listed uses, fx 6300 will suffice, both are bang for buck in their respective price ranges. it also depends on which gpu you plan to pair the cpu with.
if mid to high range single card set up, 6300 will be all you'd need. you want to cfx 7970's, then go for 8320.
Yea this^ if your Thinking about crossfire go for the 8320. If not the 6300 is a fine gaming cpu