a solid 520w+ PSU w/ 40a on the 12v is plenty of power for your PC
750w if you plan to run the GTX 670 in SLI
of the two you linked I would get the corsair but the 650w version if you don't need to run two cards. other options are the seasonic 520w & 620w PSU, PC power and cooling 600w PSU, antec's 520w & 620w PSU. plenty of options in that range.