Under the assumption that we must be taxed, I have this proposal:
Every person who makes $20,000 or more in profit ((or couple who makes $40000 or more) will pay a $1000 tax that will be divided amongst the charities of their choice, i.e. US Armed Forces inc., Unemployment Insurance LLC, Food For The Destitute (A Not For Profit Group), etc.
See how those apples fall.
Additional: As far as minarchy goes, the source of funding I find less offensive to this is that the state and local governments may only be funded by their own lotteries.