Well, if you want a pretty snail which doesn't eat plants, you want to get an apple snail, Pomacea bridgesii. It grows to about 2 inches and they mostly stay underwater, only females climb above water line to lay eggs, they do breathe air, but they have a siphon which they stick to the water line and exchange old air with new air to their lung, for that they don't need to go above water.
But if you want a snail that doesn't go above water level to lay eggs, then you might want to consider Neritina natalensis, zebra snail, they grow to about 1 inch, don't breathe air, but water and don't lay eggs above water line. The actually can't breed in fresh water, the small white eggs they lay underwater need brackish water to hatch. But they do climb off the water sometimes for no apparent reason, so you need a tight lid if you don't want to collect zebra snails from the ceiling, floor or your computer screen
You can find some more information about those snails from the pinned topic in this section.
