Living in Alexandria, I would recommend the shows in Dallas/Ft. Worth.

This one is the best in the area from what I am told:
http://www.reptileconference.com/htm2006/dfw_index.htm

I am not aware of any 'larger' breeders near Alexandria. There are several keepers in that area though, you may want to get in touch with Louisiana Gulf Coast Herp. Society as they do a big field herping event ever year in Kisachie(sp?) National Forest. It would be a good opportunity to get to know some fellow herpers.