http://www.coolermaster.outervision.com/

use this

I tend to lean on the side of caution... I'd say at least 650w, I personally would go 750 or 800 for headroom. Some may disagree.

http://www.coolermaster.outervision.com/

 

use this

http://www.extreme.outervision.com/psucalculatorlite.jspmore detailed version of the same thing. Nothing wrong with peepskill's link. Good luck pal :)

http://ca.pcpartpicker.com/user/cditacchio/saved/MvzWGX

here i put windforce cards because i could not find the galax cards on that site but ill link them and it will tell you how much they use (probably around the same) 

http://www.galax.net/US/980hof.html

hope this helped! 

NONONO, Dont go galax card. I would go EVGA or Gigabyte

They are just better cards.

EVGA 980 Classified if you have the budget

i run the rm 850 from corsair with your config 850 is more than enough :)

Use just about any PSU wattage calculator then add about 20% on to that for decent overhead and coverage from capacitor aging.

About 420W i think.