Well, I think the reference was to a real banana tree, not the shrub.
I went to Wilson Bros online nursery in Georgia, thinking I has seen this shrub there. Yes, they have it! They say it is a go for this area, but it's for zones 6 through 9, or something similar.
They have a huge selection of Southern plants for sale, probably more azaleas and Camille I've ever seen in one place. They sell mostly one, two and three gallon size plants, and some five gallons. A few plants they offer as a six pack of quart containers. They're not cheap, but they include shipping in the price. I urge all southern gardeners to check them out. Rated highly on davesgarden.