What's with PCP&C silencer? And what's with the bronze certificate?
It's one of the best PSU brands and the certificate is for efficiency, the main reason I didn't get that unit is that it wasn't Modular.
Yes it will be very sufficient and you can overclock anything in your PC with more headroom.
Measured power consumption
System in IDLE = 140 W
System Wattage with GPU in FULL Stress = 279 W
Difference (GPU load) = 139 W
Add average IDLE wattage ~10 W
Subjective obtained GPU power consumption = ~ 149 Watts
The GPU draws 150W when fully loaded, there will be no problem when you SLI.