Wanted: suggestions for calibre/linux compatible ebook reader

[M. Fioretti]

Greetings,

A family member just asked for an e-book reader for Christmas. Since I
will be the "sysadmin" of this device... here I am to ask for shopping
suggestions, because I am NOT up to date at all with current market
offers, best brands, ebook screens technologies etc. My requisites
are:

1) available on Amazon, because right now I have no better use for an
   Amazon gift card i got...

2) Linux/calibre compatible. I want to be able to manage its entire
   content with Calibre, without wasting time with software or hardware
   configuration

3) hardware-wise... I know for sure this thing will be used ONLY to
   read ebook, loaded when it is attached to my computer. So wi-fi is
   NOT needed at all. What we care about is screen quality, readable
   in all lighting conditions, battery life, reliability... screen
   size: 7/8 inches?

I am surely forgetting to ask some question, but the word is to you
now. Thanks in advance for your feedback.

Marco