Short answer: you don't need regular gaiters or snake gaiters.
More info: I've done a couple south Texas Aoudad hunts. [Regular, not snake] Gaiters aren't needed, they won't do anything (against cactus or snake). Cactus spines will go through your pants even with gaiters on, same with snakes. I wore Kuiu Guide pants (and jacket) on the Aoudad hunts and they did not get torn up.
I have have Crispi Hunter GTX (12", all leather) boots. They'll stop the spines (and snakes).
Separate from the Aoudad hunts I've done quite a bit of other hunting in Texas all times of the year. As the weather warms snakes start to come out, but at the time of year you're talking about they'll be a little lethargic (though maybe somewhat jumpier). I have snake boots that I pretty much only wear during the warmer months and only on particular properties that I hunt as snakes are not everywhere. And I don't even own snake gaiters. One of the properties I hunt I'm much more concerned about scorpions than snakes.