Hermits will kill the snails eventually. If you value snails, stay away from all crabs.
Ceriths come in a few varieties, dwarf, Caribbean, Florida, and a few others. They go all over and are particularly good for cleaning sand as are fighting and tiger conchs. My sand is always cyanobacteria and algae free thanks to my ceriths.
Astra and turbos are more sensitive to Mg levels but all snails are susceptible to Mg toxicity. Keep Mg no higher than1400ppm to maintain a healthy buffer from it. My snails dropped like flies when my Mg reached 1500+ppm. They just sat there looking drunk and slept until they starved to death. Higher levels of Mg act as a sedative to which they can't ever escape (because it's in the water) and they OD.
But astreas and turbos are good for cleaning glass and rocks. My nerites stick to the glass mainly and they come in a wide variety of colors including red, yellow, blue, white, grey, and tan.
Margarita snails are a cold water species and should be avoided because they live a very short life in our warmer tanks.
Trochus are nice because they are essentially an astrea that can flip themselves right side up (astreas can't) and are not as sensitive to Mg levels. Trochus, ceriths, and nerites will breed in your tank.
I also have gold ring cowries, aka money cowries, that are doing well. They are predominantly nocturnal and really mow down hair algae. They are super cool looking at night and have pretty shiny shells to see during the day. Because their mantle covers the entire shell when they forage at night, it never gets algae growth on it and is always pretty.
Most snails are more active during lights out, especially ceriths. But the trochus don't seem to keep any regular hours from what I noticed.