Delluser is, as usual, correct . . . and a man of few words
Unlike other parts, a poor-quality psu can damage parts of your PC, shorten its lifespan, and in extreme cases . . . worse. PSU failures cause strange symptoms, More than 50% of the hardware problems resolved here are fixed with a new psu.
The Antec you chose has been around a few years and is well known to us as a very good psu:http://www.jonnyguru.com/modules.php?name=NDReviews&op=Story4&reid=110
(You might read at least the first page as well.)
That Corsair was reviewed even better (as most Corsair units are) when introduced several years ago:http://www.jonnyguru.com/modules.php?name=NDReviews&op=Story4&reid=62
Either one is satisfactory, the Corsair is "a higher quality build".