I don't understand why someone would want to spend upwards of $1,800 on parts, then refuse to spend the money on a power supply that will run it all. Using a power supply that doesn't have enough power does cause other components to fail. Also, something that no noob ever knows is that the very first time you use a power supply, is the most power you'll ever get out of it. As it ages, it will put out less power. Even the absolute best brands put out less power as they age.
I mean, when you can get a 700 watt OCZ psu @ newegg for $129, why would you want to spend $80 for one that may have the power you require right now, but won't in a year? PSU's lose between 15 & 20% of their power for every year that they're used.
When you add the fact that you will be wanting to overclock, a 500 watt psu just isn't going to cut it, no matter how good the quality. A 600 will, for the first year, but do you really want to replace your power supply every year? I wouldn't, especially since you would spend much less by just getting what you need to begin with.
Anyway, the choice is up to you. I'd just recommend that you don't make the most common of all noob mistakes, and try to spend all of your money on components, and skimp on the power supply.