Book illustration cartoon type

Hello We want to Illustrate a book for children 8-14 - to be used in schools. Our budget is US$ 1000 for a book that will have 40 pages. We will have more books to follow because this is a collection of 5. Our preference is to make them with the same person. We will start with part of one book. This Project is to illustrate 10 pages so budget is US$250. Illustrations should be vector (Illustrator/InDesign). Cartoon style - clean and a little funny. But simple. Some images in the desired style in attached file. The pages will have a background about the main subject of the page and small drawings illustrating some paragraphs. Suggestions are welcome. We will own the rights of the project and illustrator works as ghost. We want to be able to use the characters and illustrations in advertisement, web site or another book for example. Thanks!