I would strongly suggest finding someone who is well versed in SAT essay writing.  Simple mistakes can lead to a large deduction in points.  Students who forget to answer the prompt can be marked as a 0, no matter how well they write.  I would also reminf you that no matter how good your tutor is, if you are not willing to do work outside of the sessions that you meet with your tutor, then you may be wasting your time and money.