BTW, one way to decide on tank size is look at the specs of a number of models that use the size engine you plan to use.

There is a reason the models come with certain size tanks. It's because they are designed around an engine size. And engine size determines tank size. You won't find a chart anywhere, but you don't need one.

Tower Hobbies is about the most dependable "specs" provider. They almost always describe in detail everything they sell. They're a good place for research of the sort.