I'm running about 200 watts on 10 sticks for 300gh. So I don't think that's overkill, could still use more lol. If you look at the left of my miner you'll see the kill-a-watt. It hovers between 180 - 205 watts.  But that also includes fans, hubs and pi's

http://i.imgur.com/nbc1aEN.jpg