Voice Talent to Math video-lessons

Hello, We have 91 videos with 3,5 min on average (around 5 hours and a half in total) that are recorded already with a robot voice. We will substitute the current voice with a human voice, to make it more natural, envolving, easy to emphatise and pleasant. For that we are looking for a native english speaker that is good at teaching or explaning his point of view. Mathematics knowledge is preferrable. First, before doing the 91 videos, we would like to get in touch and send the script of the first video to a trial.