Yes 650W is more than enough for a build with 7870 CF.
Out of the three PSUs listed (Corsair TX650 V2, Lepa B650-SA and XFX Core Edition PRO650W (P1-650S-NLB9)) the XFX is the only one which has the correct number of PCIe connectors (four) for two 7870s, as a single 7870 needs two PCIe connectors each.
So I would recommend you get that one.
However the 750W version is cheaper at NCIX US:
XFX ProSeries 750W Core Edition ($85)http://pcpartpicker.com/part/xfx-power-supply-p1750snlb9
And the 650W version has a $10 rebate at NCIX US as well.
This is also at a good price and a much better unit IMO:
Rosewill Capstone-750M ($110 @ Newegg / 20% off promo code)http://pcpartpicker.com/part/rosewill-power-supply-capstone750m