Toxicity, That Would Be Crazy Helpful.
Monitor - I am buying one locally. 24" Dell 1080 HD - $260 From Best Buy, Unless you can find one better/cheaper. I am going to double it as my Xbox Monitor, so that is why it's going to be so big.
Speakers/Keyboard/Mouse - Unless you can find some killer pieces cheap, I can get these locally.
Overclock? I don't know what that is or how to do it. My First Hand Built Rig so I'm not sure.
Budget - $1200