What would we do with the surplus if we really fixed health care?

OK, one last health care related discussion (I hope). This has nothing to do with the health care bill just passed, but is a hypothetical question, really. Suppose that we decided that we wanted real single payer health care. We now spend around $4500 per capita, including government and personal spending, on health care, far above what the rest of the industrialized world spends, with generally worse results when measured by life expectancy. The median household income in the U.S. is around $50,000. Would it be so awful to tax everyone at 9 percent and pay for all health care out of the pool? This would replace Medicare and Medicaid as well as the separate VA funding. Would it be seen as better or worse than the recently passed bill by conservatives and libertarians? And with the profit margin and all the inefficiencies of the current for profit system removed, what would we do with all the money left over from this tax?