I'd make it revenue-neutral for each tax bracket
Rather than completely eliminating the income tax, I'd figure out how much consumption tax the average spender in each income tax bracket would pay, and then reduce the income tax by that amount (or eliminate it entirely or increase EITC if appropriate).
Because the rich spend a lower percentage of their income than the poor, the failure to make it revenue-neutral results in a net cut for the rich. If you want to keep government funding at current levels, you'd have to increase the net tax on everyone else.