Why not the iPod Touch? Apple still sells them, and they come in 32GB, 128GB, and 256GB capacities.
$1 My music library is 25GB, my audiobook library is another 25GB or so.... how much space are you needing?
They all come with the same iOS, same Voiceover accessibility, and if using wi-fi can do everything except phone calls (not counting VOIP like facetime/Zoom/skype ....) and most (not all) iPad apps.