The opening chapter of The Sound and the Fury, as well as Of Mice and Men, sound like good things for you to read and consider for this venture. I'm fairly sure most are familiar with the general outlines of the Steinbeck novel, but the Faulkner is slightly more obscure, due to its obtuseness. Basically, the opening chapter is written from the point of view of a developmentally challenged man, whose grasp of "now" is tenuous at best, let alone his understanding of morals.

Even if you don't ultimately use it, I've found that another author's take on a challenging subject to be helpful.

I've read (and listened to it on CD) The Sound and the Fury, but I don't see Kevin that disabled. Plus, I read As I Lay Dying, which has another character who's a little off. Faulkner seemed to have a lot of characters who were a little askew at times.

I see Kevin more as a chalkboard that was partially erased by brain disease. A lot of Kevin came through, but quite a few of his thought processes were damaged. I really don't want to get into all of his issues this early because a lot of his problems have been aggravated by other people who assume somethings about him that aren't necessarily true, not that I'm saying who. All of this comes out in the second section of the story, by the way, so I really, really, don't want to say too much about how it all comes out in the end.

Oh, and thank you for the suggestion for the Of Mice and Men suggestion, but, unforturnately, I don't read Steinbeck. There's just something about his writing style that reminds me of fingernails on a chalkboard.