The Corsair 650TX V2 and the XFX are both made by Seasonic and based on the same platform. Both are excellent. Since a system with a single GTX 570 only needs a recommended 550w power supply the Corsair 600CX you linked to first would also work just fine although it is a small step down in quality from the TX V2 line.
All XFX power supplies are built by Seasonic. The ones you linked one is built by seasonic as well the V2 the other is built by CWT i would go with the XFX or V2 as Seasonic builds rock solid reliable quality power supplies and CWT although very good has a less consistent track record.