Dear Juliarx,
I am really interested in you job offer and I know I can provide what you need. I am a professional writer that started her carrier as a journalist and moved on as a freelancer. I am a hard consumer of motivational books and I did several projects like your proposition. Since you wish a rewrite of an existing book, I am not sure if it makes a great difference, but if you request, i can provide a sample and you pick the topic. I would be glad to work with you since it is a project that i can relate to easily.
Regards,
Elena Alexandru