where in the stl. to buy trochus snails?

[jamison74]

been around to marine solutions and gateway, looking for trochus and margarita snails. i have a far amount of cleaners but my astrea snails fall of, well actually my porcu puffer sometimes pluck them of the glass and they cannot right themselves. from what i have read the trochus and margaritas can. any advice on where i can get these would be greatly appreciated, thanks in advance,
jamison