Finding ebooks to buy, in the format .fb2, seems so far to be impossible, but don’t give up, you can still get a lot of ebooks free of charge.

Her: http://www.gutenberg.org/
Her: http://www.fictionbook.ru/en/

Format I have found useful are: .fb2 .pdb .txt and .html
Some of them I read in the FBReader and some in the Plucker eBook Reader.

I may have to have different format in my PC an on my 770 for the same book.

On www.gutenberg.org/ I have found books in my own language and on www.fictionbook.re/en/ I read books in English.

TTP