Some observations and questions:
- if your iPad still works, then why not use it? I still used to use my old iPad 3 until recently.
- what apps are you planning to use?
- some apps can use wifi (on your iPad) to connect to calibre or the app on your ipad can be connected through a browser. Epubs etc can be transferred over wifi.
It mostly depends on what ereader app you plan to use (if possible). Hopefully old versions of the app are still available. Regrettably Stanza isn't.
NB: I just tested all this with:
- calibre (latest) on debian jessie
- marvin epub reader on
iPad 1 (!!!! found one under some dust !!!!)
- connected from marvin to calibre (set up Content server on calibre) worked with website and opds view.
- if marvin works then most probably some other epubreader apps will work as well (for example shubook) if you can find them in the app store.