I must say after receiving this feedback I donāt think I want to purchase these anymore. You seem to have also ended up with more than you aimed to initially have. Thanks for your help.
Remember that the snails only reproduce according to the organics in your aquarium. It is not the snails themselves, but the fact that there is so much food, and someone or something has to remove this regularly, and that is where snails are so beneficial. Your water changes and filter cleaning and substrate vacuuming (aside from plants) also work to achieve this.
I would go with Malaysian Livebearing Snails as the overall best scavenger as they burrow throughout the substrate and that is a benefit. Ramshorn may damage plants, there are apparent instances of this, but MLS never eat healthy plant leaves.
Hardiness of snails was mentioned earlier...the MLS will be happy in soft to hard water; I have zero GH and they are fine. Some of the others need more calcium so they sometimes fail in soft water. My pond snails are doing well though, but in the past not so much.