I think your cutting it close. This is a pretty high estimation of the max draw you should see from each part. Real life useage will be lower, because you will never have every part at full draw at the same time.
Give the i7 150 watts if you plan to overclock
the board is around 50 watts
figure 10 watts for the ram
10w for each sata device 50 watts
and 215watts for each gtx470