Bilingual Assistant for Trucker's English Classes

I need a native Spanish speaker with very good English skills. Starting next Saturday August 8th I'm teaching several Spanish Mexican students trucker's English. I need help if they have question during the sessions. I need a strong English and Spanish native language person. I don't need expensive certified interpreters. I can pay somewhere between $25-30/hour. The teaching sessions that I'll be doing are on the following 6 Saturdays. Aug.8, Aug. 15, August 22, Aug. 29, Sept. 5, Sept. 12 from 7am to 4pm each day. A few beaks and a lunch break paid. Bonus for outstanding work and a contract for lots of future Saturdays. Bonus at end of six sessions is based perfect attendance, excellent support during sessions, and punctual on-time to class. Bonus is up to $500. Please read before responding.