I would try and find blue legged hermit crabs, they tend to be more reef safe, if you buy them a few extra shells they'll leave the snails alone, but cerith and Astraea are a good choice also nerite and trochus are great reef cleaners. Many snails have different tastes and methods of eating algae.
For me, my cuc always consists of snails, hermits, nassarius, peppermint shrimp, and a conch. I also LOVE micro brittle starfish. They are the best natural cuc. If you can find a forum member to get you some they'll work wonders.