If you're going for that type of 2-in-1, I'd recommend something from ASUS. I have one similar to
this. It is touchscreen, but you can add a mouse (which is how I use it). ASUS has excellent battery life.
But this seems like a lot to invest if all you want to do with it is play audiobooks.
Could you do something like copy the audio files to a flash drive/SD card, and plug the flash drive/SD card into a little standalone speaker?