Here is a theme that will work great with many different background pictures. It has a simple, and easy to read interface.
You must have EvolveSMS installed and have the customization pack in order for this to work.
To use this theme go to Evolve Settings -> Theme Settings -> Use Addon Theme -> Cloudy.
If you wish to use the packaged background make sure you have Addon Theme Background selected under the Use Addon Them
All old backgrounds used in this theme can be found here! -> http://goo.gl/0Mkxzk