The only thing to watch out for is that most proportional stats perform badly with some lower cost inverters. I have tried a number of back up systems and in my testing I have discovered that some cheap inverters cause a triac controller found in most proportional stats to stay on all the time. It would be tremendously sad to have a power failure and discover your snakes died from too much heat.
I have spoken to both Dion B (herpstat) and Jeff W (helix) and both say Generac work, it is why I suggest them I know they are compatible with proportional stats.
Do your research before you buy ask specifically about triac controlled thermostats. It would be sad to spend a large amount of money and end up with something just as dangerous to your pets as the power failure was in the first place. Be certain that the back up power will work with your stats.