That Cooler Master psu got a very good review by a tough reviewer:http://www.jonnyguru.com/modules.php?name=NDReviews&op=Story4&reid=134
Is it enough for 2x5850 . . . maybe . . . but as mosox said at 40A (x 12V = 480W) its a little weak on the 12V rail. Many PSUs would have more than 480W out of 600W available from the 12V rail. But a PC with 2x5850 running Furmark peaked at 478W from the wall, which means less than 425W from the psu:http://www.legitreviews.com/article/1097/12/
Since some of that power was not 12V power, there should be just enough to allow your cpu to run full out as well. But there isn't the margin we would recommend, so next year it might not be enough.
Either of the two PSUs recommended above would be much better.