[Lupin]

Kindle Touch might be nice, but that means you by your books from Amazon and if you have more than about 200 books, you can not keep them all with you. If you have a wi-fi available (or by a 3G version) that will not matter much as long as you have faith on Amazon cloud.

I do not know how kindle gets it's firmware upgrades. Typically you need to run some software which is windows-only and connect your reader to the computer. Some of the software might run on macs. If your are a Gnu/Linux user, choose device which gets updates OTA or at the minimum, you can download the firmware on the devices memory or on a memory card which you can insert in the device. At least Booken's Orizon and Odyssey are of this type: Both OTA and download into device is supported.

Do you plan to use it for other thing than reading e-books? If so, by a tablet. If not, choose device with e-paper, it is easier to your eyes plus the battery lasts much longer.

I'm not able to recommend any device as I am a newbie myself. Bookeen's Odyssey works, but still has some bugs. But then again, if you read this forum it comes soon clear that there is no such thing as "perfect" device. They all seem to have a bug or two.

I recommend state of the art model if you can spare the money: they are more likely to be supported a year from now. Used well kept reader might be also good choice if you get it at a good price.

And if you want to hack the thing, Android base devices seem to be the best bet.