A qualified charitable distribution (QCD) can only be taken from a traditional or Roth IRA. It cannot be taken from a SEP or SIMPLE-IRA. However, SEPs and SIMPLE-IRAs can be rolled over to an IRA and then QCDs can be taken from the IRA.
Generally, an unmarried person who maintains a household for dependents and is allowed to compute his or her tax based on head of household rates, which are more favorable than single person rates.