Theres lots of different kinds of sauces though. In Texas alone we probably got about 3million!
Red, green, hot, sweet, sour, etc. Sauce in a bottle, in a bowl, in a can, in a jar, flowing on something, flowing off of something, etc.
Try an image search to see if you can come up with a closer idea of what your looking for.
Wallpapers usually reflect an idea or theme of the OS in question and the personality of the person who founded it.
Look around some on the web then post some better (more detailed) descriptions of your ideas, and Im sure everyone will be glad to at least take a look into it in an effort to help you....