Is 725 watts enough for a 600 watt Gaming PC?

Buying all parts for my computer and was wondering

Depends on the number of video cards you'll be running and the quality of the power supply.

725 watts will probably be enough if you're running one GPU, but make sure it has a single +12v rail.  Also make sure the 12v rail has plenty of amps on it - I'd say at least 40A.  Stick to the major brands like Seasonic, Corsair, Cooler Master, or XFX.  There are other brands out there that do just as much for cheaper, but I know I'll get flamed if I start talking about it