Here is a great article on the various species of Turbo snails.How about "turbo" snails? are they a type of one of the snails listed above?
As far as some of the others- I found my serpent stars to be far too aggressive feeders, and the sea cucumbers just grossed me out too much to keep. I am too afraid of rock slides for sand sifters, and the only crabs I keep are porcelains. I love my shrimps, but love my corals more- and standing there batting shrimp away while a coral is trying to feed just got too time consuming.
It all depends on what other species you are planning to keep. I have a lot of slow feeders like my Fungias, Trachyphyllia, BTA, Tubastreas etc and even with the soda bottle cage things the shrimp were just too relentless about the food.