There aren't any bronze or gold rated PSUs in that category? Thermaltake is fine too, but the extra wattage here isn't really going to make a difference right away. However, it might help a bit a few years down the road, when the power supply is a bit older and starting to waver.
Some high-end PSUs come with ten year guarantees, but even those models can get a bit unreliable towards the end. The ones you've listed likely won't last that long, but they should be perfectly fine for several years at the very least. Many can and do last longer, but they're not always as reliable at that point, especially if your definition of reliable involves playing games for long stretches. The reliability is a factor of the rating though, not so much the wattage. (As always with hardware, there's some element of randomness to how well a component holds up over time.) Where the higher wattage can help is when the PSU is just beginning to falter, and you'd like to wait a bit longer to replace it.
So it's kind of a close call. Personally, I'd spend a little extra for the upgrade, especially if the amount was trivial. Having a larger margin for error is always nice. But it's not strictly necessary—the Cooler Master should still be good enough for a while, and by the time it's not, you'd probably be about ready a new PSU whether you bought that or the Thermaltake.
