Yeah, it will really work fine, and for years.
Remember, there are cheapo psu boxes out there that say 600 watts.
Look at the amps on the 12v rail. Your system will not use anywhere near that much power. If you had a different motherboard (that supported SLI), you could use a molex --> PCI-E 6 pin adapter for a second videocard and it would still have enough power. For what you have this is a high quality psu that meets you needs at a good price. If you want to spend more money, go to jonnyguru.com and look at better boxes. Brand for power supplies turns out to be an important factor.