Thoughts on snail purchase?

[pelfiredc]

Hey all,don't have any hermits anymore so I feel clear to buy new snails but not sure on type or #s, it's a 56 gal w lps and fish, live rock ect...... Nothing really bothered the lps or softies as of yet but don't want to intro any problems either. I don't have any problem algae and tank is 4 yrs old but want stirrers and rock glass crew , some Green algae on spots ect... Thanks for your thoughts