That's a difficult question to answer. It depends on many conditions, so no one will be able to tell you definitively one way or the other.
A robust pair of fancy clowns will be healthier than a weak pair of regular clowns. Likewise, clowns from the wild can be healthier or not, depending on the condition in which they are brought in, and how well they take to captivity.
You are better off only buying clowns that you can see first hand, and making sure they are hardy and healthy before you buy them.