Actually there's several places that specialize in butterflies! In fact Gainesville has a butterfly exhibit in the Natural History Musuem.
Greathouse Butterfly Farm is near me actually, and I used to have them as a client. Google shows several butterfly farms in the state, but they can ship both eggs and pupae, or even refridgerated butterflies. I even know of a place that sells silkworms.
It's a cool hobby although you have to make certain you have access to food for whichever species you want to keep.