How much wattage would i need?

[SupaJoe]

I am buiding my 1st pc and so far i have these parts:

My question is the Estimated Wattage is 667W, would 760w be good enough for it or does it need more leeway?Maybe in the future to make upgrades and so forth.

CPU: Intel Core i7-4770K 3.5GHz Quad-Core Processor

CPU Cooler: Cooler Master Hyper 212
EVO 82.9 CFM Sleeve Bearing CPU Cooler

Motherboard: MSI Z87-GD65 Gaming ATX LGA1150 Motherboard

Memory: Corsair Vengeance 16GB (2 x 8GB) DDR3-1600 Memory

Storage: Samsung 840 Series 120GB 2.5" Solid State Disk

Storage: Western Digital Caviar Blue 1TB 3.5" 7200RPM Internal Hard Drive

Video Card: MSI GeForce GTX 770 2GB Video Card (2-Way SLI)

Video Card: MSI GeForce GTX 770 2GB Video Card (2-Way SLI)
)
Case: NZXT Phantom (Black) ATX Full Tower Case

Power Supply: Corsair 760W 80+ Platinum Certified Fully-Modular ATX Power Supply

Optical Drive: Asus DRW-24B1ST/BLK/B/AS DVD/CD Writer

 

[Dark Lord of Tech]

850w is a good place to be with 2 770's.

Here's a nice unit made by SEASONIC.

PCPartPicker part list / Price breakdown by merchant / Benchmarks

Power Supply: Antec HCG M 850W 80+ Bronze Certified Semi-Modular ATX Power Supply ($119.99 @ NCIX US)
Total: $119.99
(Prices include shipping, taxes, and discounts when available.)
(Generated by PCPartPicker 2013-11-23 20:14 EST-0500)