Yeah... redtail sharks are kick-A bullies. If you like the look, the rainbow shark is much more peaceful.
And I'd have a school of 12 or so of either the gold or tiger barbs. Snails... the barbs might eat them, might not. If you don't overfeed the fish, then you shouldn't have a snail problem.
"One day...one day, this path will lead us to the White City, and the tower guard will take up the call: the Lords of Gondor have returned!"
–Boromir, The Lord Of The Rings