It doesn't even need to be Gold efficiency. If it has 80 PLUS (regular, not the 230V Internal), then you know it will support a full range of input voltages.
As for hold up time: Just because something is Gold or Platinum or whatever doesn't mean it has the correct (correct as-in meets Intel's spec of 16ms) hold up time.
But if it doesn't have 16ms hold up time, but it does support full range input voltage, you should still be ok. Because as the voltage drops, the PSU will continue to work until the AVR kicks in. On a full range PSU, the voltage can drop all the way to 100V and it should still operate normally without relying on the charge of the bulk cap to keep things going.