What kind of power supply will i need for my rig?

Seriously, you don't need more than a 450W power supply if it's allocated properly. Shop for a supply that offers at least 35 Amps of 12V, 20 amps on 5V, and as little as possible on 3.3v. Beyond that is buying capacity you'll never use. Buying a bigger supply won't make it last longer, and you will get peak efficiency around 80% load. Some of the silly big power supplies are optimized to deliver peak efficiency around 350W though since that's where almost everybody is running at.