fishkid6692, you can get airstones from your LFS, i think it would be a waste of a credit card payment to order airstones or a sponge filter for that matter online. you can get both at any petstore that has fish supplies.
and to answer your question about whether to take the babies out after they hatch; if you wait that long, chances are that you will have no babies to collect. if the other tank inhabitants havent eaten the eggs already they will certainly eat the fry, and the clowns may even do the same as well. the best thing to is figure out what spot the clowns like to spawn when they actually start to and then place some removable structure there like a fake rock, ceramic tile and i hear that a plexiglass or acrylic peice works too. put that in the spot and when they lay on that, pull it out and place it into the grow out tank. be prepared to be bitten by the clowns when this happens or anytime you plan to put your hand in the tank, they like to go for the spot between your fingers!