I don't even have kids yet and I'm also only able to complete books via sped-up audiobooks. It's a really great way to get through them.

For fiction, go for something with a professional narrator. Jim Dale's Harry Potter series is a good example. They can make it into a modern-day radio drama. But for non-fiction, I prefer if the author reads it. Authors imbibe an excitement to the reading of non-fiction; professionals often come across as monotone and I can't focus on them.