[Deiussum]

I'm no expert on this type of shot, but I think I like the version you have on SmugMug the best. The last one is good too, but the bright parts of the wall look awful close to being blown out.

You probably already know this or have already figured it out, but the reason for the banding in the first one is because GIF images support a maximum of 256 different colors as compared to the 16 million supported by JPEGs. It is a format better suited for buttons and other stuff that doesn't require a wide range of colors.