Just so you are aware its a bit of a crap shoot with the peppermint shrimp.
I recently bought 10 of them and have yet to see a difference in the amount of aiptasia in the tank. I thought that having 10 of them in the tank would cause them to compete for food and make the aiptasia's a prime target. Not so as of yet.
If you decide to try the peppermint shrimp, attempt to control the amount of left over food in the tank after feeding. I was warned by fellow RS members that they are great scavangers and may not eat the aiptasias if they can get the other food.
I have since started treating the aiptasias with a very small syringe and lemon juice. It seems to work.