That is ko888 that talks all professional and proper like that not all members here do that mate he knows power supplies like the back of his hand.I will give you my way of confirming it wait for it...wait.... your good no worries.lol.
The Antec High Current Gamer Series 520W (HCG-520) hasn't been discontinued yet. This one should be your choice, if budget is a concern.
Its +12 Volt continuous current rating of 40 Amps is the highest of the three PSU models you've listed. It'll have no problem powering a system with a Radeon HD 7950 or a Radeon HD 7870 or a Radeon HD 7850 or a Radeon HD 7770 GHz Edition.
Total Power Supply Wattage is NOT the crucial factor in power supply selection!!! Total Combined Continuous Power/Current Available on the +12V Rail(s) @ 50°C ambient temperature, is the most important factor.