Holy crap. This is your current computer or a build that you're considering purchasing? For one 980 Ti, your power supply has more than sufficient power. If you plan to SLI, then you'll come up a little bit short, especially with that CPU.
Power supply: If you can afford it, go for a EVGA gold rated unit. I think the 1,000 watt would be a great purchase for someone like you. It would give you the option to upgrade to SLI or CF for either a 980 Ti or 290X in the future. Or for $20 more, you could get the 1,300 watt unit. I have one of those and they are great. Some of the cables are red colored instead of black, which is annoying, but overall it's a great power supply. It's an over-buy but it allows me to know that I can upgrade to anything in the future and not be concerned. The only two card setup my power supply can't handle is two R9 295X2 in CrossFire, but technically that represent 4 GPUs.
http://www.newegg.com/Product/Product.aspx?Item=N82E16817438010&cm_re=evga_g2-_-17-438-010-_-Product
http://www.newegg.com/Product/Product.aspx?Item=N82E16817438011&ignorebbr=1&cm_re=evga_g2-_-17-438-011-_-Product