Where would I be able to buy a cat costume?

This ISNT for halloween or little kids this is for a dance recitel I have to do, which involves doing a piece from macavity from cats the musical anywhere where I could rent one or even buy one (!) and I don't what the price is :) Hope you can help, btw if your wondering they are tight, lycra typew leotard jumpsuits that are different dark colours and are easy to move in.