If you are trying to save the most amount of money that you can without making things overly complex, I would recommend setting up an individual 401k plan. Most large brokerages can help you handle this. Mine is with Fidelity. You can contribute the maximum 401k contribution, $13,000 this year, $14,000 next year (more if you are at least age 50). You can then also make the same contributions that you can with the SEP (25% of earnings up to the $205,000 earnings limit). You won't need multiple plans to do it.
LawGirl