APU + HD 6670 PS requirement

Hey guys,

I am going to build an APU system this month and just wondering if a 400 W PS would be enough to power this comp

A8-3850 processor
HD 6670 video card
4 x 2 GB PC 1600
1 SATA HD
1 DVD Drive
2 case fans

This computer will be on for at least 20 hours a day and I am thinking of getting this power supply

FSP Group AURUM GOLD 400W.
http://www.newegg.com/Product/Product.aspx?Item=N82E168...

Is 400 W enough or do I have to get the 500 W version?