PSUs run the most efficient at around 40-70% fwiw; your system will peak around 180-250W depending on what GPU you're gonna use (Radeon HD 7xxx are the most efficient cards afaik), if any, and idle would be around 100-150W I guess so there's really no point in getting a 500W PSU.
http://en.wikipedia.org/wiki/80_Plus...certifications
Obv your system will need like 15-25% more Watts if you overclock (rough estimate). As sixfour mentioned you should look to get a "k" CPU ("k" means unlocked multiplicator) as they're basically designed for (under- and) overclocking.
As for GPU power consumption, the PCIe slot itself supplies 75W max, any additional 6pin PCIe connector supplies another 75W, and 8pin connectors supply up to 150W each. Just so you can calculate actual system requirements.
I personally wouldn't be too happy with that MSI board, first of if you really don't ever consider plugging a second graphics card you don't need two PCIe x16 slots (even if you're going to you'd be limited in card length due to the SATA ports), but my main concern would be the SATA connectors; there are only two SATA3 con's where I personally would want 4. Also it looks like the board only supports 1333MHz RAM (faster RAM is downwards compatible though).
Samsung 840 SSDs seem to offer the best value you can get for your money. Doesn't even need to be the 'Pro' variant imo.