Should you look for an author or an illustrator (or both) for your next author visit? Both have advantages:
Authors can read the stories they’ve written and talk about the writing and editing process, how they come up with ideas, and what it’s like to be an author.
Illustrators typically offer a slightly different presentation, often focusing on telling the stories using the visual elements they’ve created for the stories written by the authors of the books they’ve illustrated.
Some authors are also illustrators (see, for example, Kristin Joy Pratt-Serafini). Author/illustrators can be fascinating people for students to meet, since they both write and create the visual elements of the books they author.
Some students respond better to writers, and some to illustrators. In the end, you should pick an author or illustrator who your students can appreciate and respect. Both authors and illustrators can provide valuable inspiration for your students. Just be sure to find a speaker who has experience relating to the children they’re hoping to inspire and you should have a successful author visit whether you select an author or an illustrator!