Professional children's book illustrator for series of books.

I have several children's picture books in a series to illustrate. I am looking for a professional creative children's book illustrator who expert and fast in his/her job for long term cooperation. This post is for the first book with the possibility of continuing on the rest of the books. Figures vary in different pages in the book. I am looking for a full-page (spread page) illustration with a detailed background in colour for each page in high resolution and source file with commercial use right as well. It will be 15 design that each of them goes to spread pages in front of each other + 1 book cover. Total 16 design. Artists that have experience in children's book design and illustration will be considered only.