Leopard Frogs in Arizona

Well I don't really care if they eat the koi fry or not, there are too
many in the pond anyway! I'd rather frogs then toads, as I think the
frogs will stay closer to the water and I don't need to worry about
the dogs playing with them too much.
I want to find a supply of grown up ones, taking spawn from the wild
is like spinning the wheel, you don't know what you might get!