pomacea bridgessi (mystery/apple snails) are a good choice. They require both sexes to reproduce and most often lay their eggs above the waterline which makes it easy to remove the eggs and prevent and overpopulation. If eggs are laid and removed, its best to freeze or smash them before discarding.
I would suggest Apples too, am more partial though to the brigs... I've had just 4 in my tank forever. I am guessing they are all the same sex or they just aren't that interested in each other.... never had a clutch yet.
I have five different aquariums. The ones I'm thinking of have a small bichir, a betta, pygmy cory, small loaches and ghost shrimp. I'll be bringing home more pygmy corys tomorrow and a couple of banjo catfish. 50% off!