In any case, your writing will speak for itself. Most editors will tell you that they can tell if a project interests them by reading the first three sentences. They do not need to be told that your kids, grandkids, students, or dog loved your story, so don't even go there. The editor who purchases your picture book manuscript will ultimately choose the illustrator. Except in rare circumstances, it is seldom a good idea to collaborate with an illustrator.
Illustrators are better off researching the market and submitting their portfolios for assignments.
Don't illustrate it yourself unless you are a professional. There is also no need to describe the illustrations in your submission. If your manuscript doesn't come to life visually without your explaining it, then the writing probably needs work. Okay, I researched and networked and sent out my manuscript. All I'm getting back, if anything, are form rejections.