http://www.clockworkreptile.com/ usually has some leopard geckos when vending at the RMRE shows... I know there's several more but the names escape me at the moment.
A good thing to try is joining up the coloradoherps yahoo group if you can, and asking there, http://pets.groups.yahoo.com/group/coloradoherps/ a lot of breeders are members and could probably help you out