How much PSU should I need?

I am thinking of getting another 7870 and was wondering if i tould need a new PSU also.

 

Specs: http://pcpartpicker.com/p/rzPM

You should be fine, but I would probably pick up a 700-750W if you plan on overclocking both cards.

Go ~50w over whatever they say to go to.

http://images10.newegg.com/BizIntell/tool/psucalc/index.html

I don't have enough so that is why I was asking. I am undecided between A LOT of things. Idk wether to get another card, a cooler, games, memory, or save for a month to get a Canon Rebel T3i