If its a decent 650watt power supply then it should be fine. I presume this is what they recommend and as such it should run that setup ok. Never heard of Atrix so can't say if they are any good.
I have a Tagan one and its excellent and I expect to use it on my next PC as well.
Wait and see would be what I would say. If you can find reviews of the power supply and decide its not that great then get a decent branded one.