Oil, Copper and Iron Down, How far will they go? What stocks to get?

Title pretty much says it all. With oil, copper and iron down when would be a good time to buy in and what stocks would you go with looking at long term.

I have been looking at FCX, VNR, CBI, APA, XOM

All of them have smashed their previous 52 week lows with FCX dropping 13% thus far today. I was thinking to let them settle a week or two and jump but wanted to see what you guys think.

Thanks for any feed back!