Libertarians oppose taxes for both reasons. Since there are both compelling economic arguments, and moral arguments, we often get along quite well, and even complement each other.

Is there data that shows that no taxes allows for a more prosperous society than does some level of taxes?

This is more tricky than it seems actually, for example, lets say government A steals $1000 from Joe and gives it to Jane, and government B passes a regulation that causes Joe to spend $1000 more on health care, but Jane to get a $1000 more in health related fees. Technically, the effect is the same, even though government B has no taxes. Or also, government A taxes you $1000, but government B prints up money so that your annual pay buys $1000 less. Once again, the effect is the same, but government B has no taxes.

However, that being said. We can and do empirically measure the way the state controls things, and how much that costs, and we can and do rank states ie http://heritage.org/index or http://freedominthe50states.org

There is definitely a strong coloration between prosperity and liberty from state economic control.