Fellow fanfic reader here.
Although I've now switched to a Paperwhite (jailbroken), I thought the Sony PRS-350 paired with PRS Plus custom firmware was pretty great. I even had it setup to display hierarchical collections. Alas, lack of built-in light was a pretty big deterrent for my usage. Since you don't need built-in lighting or wi-fi, it could be worth a try if you want something smallish.