That has NOTHING to do with how much power your PSU can deliver and how much power your system NEEDS.
Like VGKitov, I would NOT recommend any mid-high end GPU without SERIOUSLY considering upgrading the PSU!
Agreed, especialy if the PSU is old which means it's components have aged.
Тhe OP seems to have made his decision, so all I can do is wish him good luck.
PS Almost all PSU fails are due to the PSU itself and not a power surge.