The Cooler Master Elite 460 offers up 324W on the 12V. The 460 Extreme power plus offers 312W on the 12V. With either Cooler Master 460W, that's cutting it close to the 'Full Stress' load mention above since most of the wattage demand will be over the 12V rail.
This lowest-level PSU I'd recommend to run a single 460, 560, 560 ti:http://www.newegg.com/Product/Product.aspx?Item=N82E16817139027&Tpk=corsair%20500W
The CX500 gives you over 400W available on the 12V.