What I had to do was to call all live rat(mice in your case) breeders in my area, using kingsnake classifieds to locate any in florida or georgia. If they were too far away(three hours or more) I would ask them if they knew someone closer to me. Usually that gave me another person to call. Eventually(two days and over 25 calls/emails) I found a GREAT guy who delivers the live rats to my workplace. It's happens that it's on his route, and he's a nice guy!
So that's my advice, if you want live mice, start calling anyone even near you, the same state. And ask, be SUPER nice, and absolutely polite no matter what, and hopefully you'll locate a nearby source.
Wolfy