Nice looking tank.
I personally like a variety of snails, I have turbos, nassarius, ceriths, nerite (nice because they hide during the day), astreas (don't like these guys, can't flip themselves over), trochus (can flip themselves over, don't get huge, and eat a lot), and a bunch of hitchhiker snails. I need some more, but i like the variety, because they all prefer different things, and that way everything gets covered.