- Touch series are arguably the "current edition" kindles. This is the KTouch and the Paperwhite.
- What's "better"? Some have other means of data input, more or less storage space, higher or lower resolution and there's now one with illumination. In fact, the hardware is also a bit different, but K1, K2 and arguably KDX aside, that's not so noticable. The change in software from K3 to K4 (and to some extent K4 to K5) is more relevant, but I would classify it as "being different" rather that "better".
- As for the Paperwhite, that should be obvious from looking at the current threads. And some minor issues are present with other devices, but they are not likely to bite you for "light use", especially considering the purpose you're describing.
- Yep, generic connectors. So you can use generic chargers. Well, chargers can break and behave badly, just keep that in mind when you notice your $1.50 USB charger plug burst into flames.
- legit and working.
If I were in your position and had to turn every dollar twice, I'd settle with the cheapest one I could get my hands on, except for K1 and K2 (KDX won't be the cheapest and if it were, it would be a nice bargain).